Equalizer for a Suspension System

ABSTRACT

An equalizer for a suspension system for a trailer is configured to absorb or dampen the harsh shocks or vibrations coming off of the leaf springs proximate to a center frame hangar, thus allowing for a “softer” ride. The equalizer utilizes one or two independent equalizer arm assemblies or castings which are each rotatably secured within the equalizer. Each equalizer arm assembly or casting is operatively associated with one of the leaf springs such that upon upward movement of the leaf spring, the associated equalizer arm assembly or casting is forced to rotate within the equalizer and to deform a shock absorber provided within the equalizer. The shock absorber, upon the deformation thereof, absorbs the harsh shocks or vibrations which would otherwise normally be transferred from the leaf springs, to the equalizer, and thus to the frame of the trailer.

CROSS-REFERENCE AND INCORPORATION BY REFERENCE

This application is a Continuation-In-Part of U.S. patent applicationSer. No. 11/505,382, entitled “Equalizer for a Suspension System”, filedAug. 17, 2006, which is a Continuation-In-Part of U.S. patentapplication Ser. No. 11/208,963 filed Aug. 22, 2005. The entirety ofU.S. patent application Ser. Nos. 11/505,382 and 11/208,963 is herebyincorporated by reference.

BACKGROUND OF THE INVENTION

The invention is generally directed to an equalizer for a suspensionsystem used in vehicles or trailers having multiple axles, e.g., tandemor tri-axles with double eye springs, such as recreational vehicles,mobile homes and light trailers of all types.

A prior art suspension system 20 currently used on trailers incorporatesan equalizer 22 such as the one shown in FIG. 1. The suspension system20 is mounted on a frame 24 of the left side of the trailer and another,identical suspension system 20 is mounted on the frame 24 of the rightside of the trailer. Only the suspension system 20 mounted on the frame24 of the left side of the trailer is shown in FIG. 1. The suspensionsystem 20 includes the equalizer 22, a front leaf spring 26, a rear leafspring 28, a front shackle or link 30 and a rear shackle or link 32.

The equalizer 22 is generally triangular in shape, having a first endcorner 34, a second end corner 36 and a third end corner 38. Otherequalizers of the prior art may be curved rather than triangular inshape. The equalizer 22 is generally formed of cast iron and is rigid.The first end corner 34 of the equalizer 22 is attached to a centerframe hangar 40, which depends from the frame 24 of the trailer, at apoint A. The second end corner 36 of the equalizer 22 is pivotallymounted to a first end 42 of the front shackle 30 at a point B. Thethird end corner 38 of the equalizer 22 is pivotally mounted to a firstend 44 of the rear shackle 32 at a point C.

A second end 46 of the front shackle 30 is pivotally mounted to a rearend 48 of the front leaf spring 26 at a point D. A front end 50 of thefront leaf spring 26 is attached to the frame 24 of the trailer at apoint E.

A second end 52 of the rear shackle 32 is pivotally mounted to a frontend 54 of the rear leaf spring 28 at a point F. A rear end 56 of therear leaf spring 28 is attached to the frame 24 of the trailer at apoint G.

A front axle 58 is positioned on the forward leaf spring 26 generallyequidistantly between point D and point E. A rear axle 60 is positionedon the rear leaf spring 28 generally equidistantly between point F andpoint G.

To the extent possible, road shock and vibrations from tires of thetrailer are transferred to the front and rear axles 58, 60, and areabsorbed by the front and rear leaf springs 26, 28, respectively. PointsA, E and G are the contact points through which the road shock is passedto the frame 24. The equalizer 22 basically has only one purpose forbeing including in the suspension system 20, which is to equalize theweight on both the front and rear axles 58, 60 as the tires pass overuneven terrain. For example, an upward motion of the front leaf spring26 results in a downward motion of the rear leaf spring 28.

The equalizer 22, however, is not configured to dampen or absorb theharsh shocks or vibrations coming off the rear end 48 of the front leafspring 26 and the front end 54 of the rear leaf spring 28 proximate tothe center frame hangar 40, which would thus allow for a “softer” ride.The equalizer 22 of the prior art has been in use without a singledesign change for at least the past forty (40) years.

Thus, there is a need for an equalizer which overcomes theaforementioned disadvantages. The present invention provides such anequalizer. Features and advantages of the present invention will becomeapparent upon a reading of the attached specification, in combinationwith a study of the drawings.

SUMMARY OF THE INVENTION

Briefly, and in accordance with the foregoing, the invention providesequalizers for a suspension system for a trailer or the like which isconfigured to equalize the weight on the axles of a trailer as tires ofthe trailer pass over uneven terrain, but which also is configured todampen or absorb the harsh shocks or vibrations coming off of the leafsprings proximate to one or more center frame hangars, thus allowing fora “softer” ride. The equalizers utilize one or two independent equalizerarm assemblies which are each rotatably secured within the equalizer.Each equalizer arm assembly is operatively associated with one of theleaf springs such that upon upward movement of an associated leafspring, the associated equalizer arm assembly or casting is forced torotate within the equalizer and to deform a shock absorber providedwithin the equalizer. The shock absorber, upon the deformation thereof,absorbs the harsh shocks or vibrations which would otherwise normally betransferred from the leaf springs, to the equalizer, and thus to theframe of the trailer.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the invention which are believed to be novel aredescribed in detail hereinbelow. The organization and manner of thestructure and operation of the invention, together with further objectsand advantages thereof, may best be understood by reference to thefollowing description taken in connection with the accompanying drawingswherein like reference numerals identify like elements in which:

FIG. 1 is a view of a prior art equalizer incorporated into a suspensionsystem which is mounted on a frame of a trailer;

FIG. 2 is a view of a first embodiment of an equalizer whichincorporates the features of the present invention incorporated into asuspension system which is mounted on a frame of a trailer;

FIG. 3 is a perspective view of a base plate of the first embodiment ofthe equalizer;

FIG. 4 is a front view of the base plate illustrated in FIG. 3;

FIG. 5 is a perspective view of a secondary base plate of the firstembodiment of the equalizer;

FIG. 6 is a front view of the secondary base plate illustrated in FIG.5;

FIG. 7 is a perspective view of an equalizer arm of the first embodimentof the equalizer;

FIG. 8 is a front view of the equalizer arm illustrated in FIG. 7;

FIG. 9 is a perspective view of a lower shock plate of the firstembodiment of the equalizer;

FIG. 10 is a front view of the lower shock plate illustrated in FIG. 9;

FIG. 11 is a perspective view of an upper shock plate of the firstembodiment of the equalizer;

FIG. 12 is a front view of the upper shock plate illustrated in FIG. 11;

FIG. 13 is a perspective view of a reinforcement plate of the firstembodiment of the equalizer;

FIG. 14 is a front view of the reinforcement plate illustrated in FIG.13;

FIG. 15 is a perspective view of a shock absorber of the firstembodiment of the equalizer;

FIG. 16 is a perspective view of an upper pivot tube of the firstembodiment of the equalizer;

FIG. 17 is a side view of the upper pivot tube illustrated in FIG. 16;

FIG. 18 is a perspective view of a lower pivot tube of the firstembodiment of the equalizer;

FIG. 19 is a side view of the lower pivot tube illustrated in FIG. 18;

FIG. 20 is a perspective view of a fastening member of the firstembodiment of the equalizer;

FIG. 21 is a perspective view of a securing member of the firstembodiment of the equalizer;

FIG. 22 is a perspective view of a shock spacer of the first embodimentof the equalizer;

FIG. 23 is a side view of the shock spacer illustrated in FIG. 22;

FIG. 24 is a perspective view of an equalizer arm assembly of the firstembodiment of the equalizer;

FIG. 25 is a front view of the equalizer arm assembly illustrated inFIG. 24;

FIG. 26 is a bottom view of the equalizer arm assembly illustrated inFIG. 24;

FIGS. 27-32 are perspective views illustrating the formation of thefirst embodiment of the equalizer;

FIG. 33 is a front view of the first embodiment of the equalizerrotatably secured to a center frame hangar of a trailer about a firstpoint of the equalizer;

FIG. 34 is a front view of the first embodiment of the equalizerrotatably secured to the center frame hangar of the trailer about asecond point of the equalizer;

FIG. 35 is a side view of the first embodiment of the equalizerrotatably secured to the center frame hangar as illustrated in FIG. 33;

FIG. 36 is a cross-sectional view of the first embodiment of theequalizer rotatably secured to the center frame hangar taken along line36-36 of FIG. 35;

FIG. 37 is a cross-sectional view of the first embodiment of theequalizer being rotated upwardly and to the left, relative to theposition of the equalizer shown in FIG. 36, where a shock absorber isbeing deformed in order to absorb or dampen harsh shocks or vibrationscoming off of a rear end of a front leaf spring of the suspensionsystem;

FIG. 38 is a cross-sectional view of the first embodiment of theequalizer being rotated upwardly and to the right, relative to theposition of the equalizer shown in FIG. 36, where a shock absorber isbeing deformed in order to absorb or dampen harsh shocks or vibrationscoming off of a front end of a rear leaf spring of the suspensionsystem;

FIG. 39 is a view of a second embodiment of an equalizer whichincorporates the features of the present invention incorporated into asuspension system which is mounted on a frame of a trailer;

FIG. 40 is a perspective view of the second embodiment of the equalizerwhich incorporates the features of the present invention;

FIG. 41 is a front view of the equalizer illustrated in FIG. 40;

FIG. 42 is a side view of the equalizer illustrated in FIG. 40;

FIG. 43 is a cross-sectional view of the equalizer taken along line43-43 of FIG. 41;

FIG. 44 is a perspective view of the equalizer of FIG. 41 with a firstbase plate and a first secondary base plate removed therefrom;

FIG. 45 is a front view of a base plate of the equalizer illustrated inFIG. 40;

FIG. 46 is a bottom view of the base plate illustrated in FIG. 45;

FIG. 47 is a perspective view of a secondary base plate of the equalizerillustrated in FIG. 40;

FIG. 48 is a front view of the secondary base plate illustrated in FIG.47;

FIG. 49 is a side view of the secondary base plate illustrated in FIG.47;

FIG. 50 is a perspective view of an equalizer arm casting of theequalizer illustrated in FIG. 40;

FIG. 51 is a front view of the equalizer arm casting illustrated in FIG.50;

FIG. 52 is a side view of the equalizer arm casting illustrated in FIG.50;

FIG. 53 is a bottom view of the equalizer arm casting illustrated inFIG. 50;

FIG. 54 is a perspective view of an upper shock plate of the equalizerillustrated in FIG. 40;

FIG. 55 is a front view of the upper shock plate illustrated in FIG. 54;

FIG. 56 is a top view of the upper shock plate illustrated in FIG. 54;

FIG. 57 is a front view of a reinforcement plate of the equalizerillustrated in FIG. 40;

FIG. 58 is a side view of the reinforcement plate illustrated in FIG.57;

FIG. 59 is a perspective view of a shock absorber of the equalizerillustrated in FIG. 40;

FIG. 60 is a front view of the shock absorber illustrated in FIG. 59;

FIG. 61 is a side view of the shock absorber illustrated in FIG. 59;

FIG. 62 is a perspective view of a spacer of the equalizer illustratedin FIG. 40;

FIG. 63 is a front view of the spacer illustrated in FIG. 62;

FIG. 64 is a side view of the spacer illustrated in FIG. 62;

FIG. 65 is a perspective view of a bushing of the equalizer illustratedin FIG. 40;

FIG. 66 is a front view of the bushing illustrated in FIG. 65;

FIG. 67 is a side view of the bushing illustrated in FIG. 65;

FIG. 68 is a perspective view of a plug member of the equalizerillustrated in FIG. 40;

FIG. 69 is a front view of the plug member illustrated in FIG. 68;

FIG. 70 is a side view of the plug member illustrated in FIG. 68;

FIG. 71 is a perspective view of an upper pivot tube of the equalizerillustrated in FIG. 40;

FIG. 72 is a front view of the upper pivot tube illustrated in FIG. 71;

FIG. 73 is a side view of the upper pivot tube illustrated in FIG. 71;

FIG. 74 is a side view of the equalizer arm casting having bushingssecured therein;

FIG. 75 is a perspective view of a fastening member of the equalizer ofFIG. 40;

FIG. 76 is a perspective view of a securing member of the equalizer ofFIG. 40;

FIG. 77 is a view of a third embodiment of an equalizer whichincorporates the features of the present invention incorporated into asuspension system which is mounted on a frame of a trailer;

FIG. 78 is a perspective view of the third embodiment of the equalizerwhich incorporates the features of the present invention;

FIG. 79 is a front view of the equalizer illustrated in FIG. 78;

FIG. 80 is a side view of the equalizer illustrated in FIG. 78;

FIG. 81 is a cross-sectional view of the equalizer taken along line81-81 of FIG. 79;

FIG. 82 is a perspective view of the equalizer of FIG. 78 with a firstbase plate and a first secondary base plate removed therefrom;

FIG. 83 is a front view of a base plate of the equalizer illustrated inFIG. 78;

FIG. 84 is a bottom view of the base plate illustrated in FIG. 83;

FIG. 85 is a perspective view of an equalizer arm casting of theequalizer illustrated in FIG. 78;

FIG. 86 is a front view of the equalizer arm casting illustrated in FIG.85;

FIG. 87 is a side view of the equalizer arm casting illustrated in FIG.85;

FIG. 88 is a bottom view of the equalizer arm casting illustrated inFIG. 85;

FIG. 89 is a perspective view of a shock absorber of the equalizerillustrated in FIG. 78;

FIG. 90 is a front view of the shock absorber illustrated in FIG. 89;

FIG. 91 is a side view of the shock absorber illustrated in FIG. 89;

FIG. 92 is a side view of the equalizer arm casting having bushingssecured therein;

FIG. 93 is a perspective view of a secondary base plate of the equalizerillustrated in FIG. 78;

FIG. 94 is a front view of the secondary base plate illustrated in FIG.93;

FIG. 95 is a side view of the secondary base plate illustrated in FIG.93;

FIG. 96 is a side perspective view of the rotatable securement of thetwo equalizer arm castings of the equalizer illustrated in FIG. 78;

FIG. 97 is a bottom perspective view of the rotatable securement of thetwo equalizer arm castings of the equalizer illustrated in FIG. 78;

FIG. 98 is a view of a fourth embodiment of an equalizer whichincorporates the features of the present invention incorporated into asuspension system which is mounted on a frame of a trailer;

FIG. 99 is a perspective view of the fourth embodiment of the equalizerwhich incorporates the features of the present invention;

FIG. 100 is a front view of the equalizer illustrated in FIG. 99;

FIG. 101 is a side view of the equalizer illustrated in FIG. 99;

FIG. 102 is a perspective view of the equalizer of FIG. 99 with a firstbase plate and a first secondary base plate removed therefrom;

FIG. 103 is a top view of an alignment bracket of the equalizerillustrated in FIG. 99;

FIG. 104 is a front view of the alignment bracket illustrated in FIG.103;

FIG. 105 is a side view of the alignment bracket illustrated in FIG.103;

FIG. 106 is a perspective view of an upper shock plate of the equalizerillustrated in FIG. 99;

FIG. 107 is a top view of the upper shock plate illustrated in FIG. 106;

FIG. 108 is a front view of the upper shock plate illustrated in FIG.106;

FIG. 109 is a front view of a reinforcement plate of the equalizerillustrated in FIG. 99;

FIG. 110 is a side view of the reinforcement plate illustrated in FIG.109;

FIG. 111 is a perspective view of a shock absorber of the equalizerillustrated in FIG. 99;

FIG. 112 is a front view of the shock absorber illustrated in FIG. 111;and

FIG. 113 is a side view of the shock absorber illustrated in FIG. 111.

FIG. 114 is a perspective view of the fifth embodiment of the equalizerwhich incorporates the features of the present invention;

FIG. 115 is a front view of the equalizer illustrated in FIG. 114;

FIG. 116 is a side view of the equalizer illustrated in FIG. 114;

FIG. 117 is a exploded view of the equalizer illustrated in FIG. 114;

FIG. 118 is a front view of a first base plate of the equalizerillustrated in FIG. 114;

FIG. 119 is a front view of a second base plate with an upper shockplate attached of the equalizer illustrated in FIG. 114;

FIG. 120 is a perspective view of a shock absorber of the equalizerillustrated in FIG. 114;

FIG. 121 is a perspective view of a spacer of the equalizer illustratedin FIG. 114;

FIG. 122 is a front view of the spacer illustrated in FIG. 121;

FIG. 123 is a cross-sectional view of the spacer illustrated in FIG.121;

DETAILED DESCRIPTION

While this invention may be susceptible to embodiment in differentforms, there is shown in the drawings and will be described herein indetail, specific embodiments with the understanding that the presentdisclosure is to be considered an exemplification of the principles ofthe invention, and is not intended to limit the invention to that asillustrated.

It is to be understood that where dimensions are used in the descriptionof the illustrated embodiments, these dimensions are those for thepreferred embodiments of the illustrated embodiments. It is to befurther understood that modifications to the dimensions may be made inkeeping with the spirit of the invention, and that the dimensions arenot intended to limit the invention to those dimensions described. Also,it is also to be understood that the drawings may not be drawn to scalein conformance with the dimensions described herein.

Attention is now directed to the various embodiments of the invention. Afirst embodiment of an equalizer 100 is illustrated in FIGS. 2-38. Asecond embodiment of an equalizer 500 is illustrated in FIGS. 39-76. Athird embodiment of an equalizer 800 is illustrated in FIGS. 77-97. Afourth embodiment of an equalizer 1100 is illustrated in FIGS. 98-113. Afifth embodiment of an equalizer 1500 is illustrated in FIGS. 114-123.Reference numerals of the first embodiment are in the one, two, threeand four hundreds. Reference numerals of the second embodiment are inthe five, six and seven hundreds. Reference numerals of the thirdembodiment being in the eight, nine and ten hundreds. Reference numeralsof the fourth embodiment being in the eleven, twelve, thirteen andfourteen hundreds. Reference numerals of the fifth embodiment being inthe fifteen, sixteen, and seventeen hundreds.

Attention is directed to the first embodiment of the equalizer 100. Theequalizer 100 is provided for use in a suspension system 102, asillustrated in FIG. 2, to equalize the weight on both the front and rearaxles 418, 420 as the tires pass over uneven terrain (as does theequalizer 22 of the prior art suspension system 20), as well as todampen or absorb the harsh shocks or vibrations coming off a rear end408 of a front leaf spring 394 on which the front axle 418 ispositioned, and a front end 414 of a rear leaf spring 396 on which therear axle 420 is positioned, proximate to the center frame hangar 372,thus allowing for a “softer” ride. As best illustrated in FIGS. 32-36,the equalizer 100 includes first and second base plates 104 a, 104 b,first and second secondary base plates 106 a, 106 b, first and secondequalizer arms 108 a, 108 b, first and second lower shock plates 110 a,110 b, first and second upper shock plates 112 a, 112 b, a reinforcementplate 114, first and second shock absorbers 116 a, 116 b, first, second,third and fourth upper pivot tubes 119 a, 119 b, 119 c, 119 d, first andsecond lower pivot tubes 120 a, 102 b, first, second and third fasteningmembers 122 a, 122 b, 122 c, first, second and third securing members124 a, 124 b, 124 c, and a base or shock spacer 126.

FIGS. 3 and 4 illustrate the first base plate 104 a, which is preferablyformed of a forged, cast or fabricated metal. The first base plate 104 ais identical in shape and configuration to the second base plate 104 b.As such, only the first base plate 104 a is described with theunderstanding that the description of the second base plate 104 b wouldbe identical. The elements of the first base plate 104 a will havereference numerals ending in “a”. As such, it is to be understood thatthe elements of the second base plate 104 b will have like referencenumerals ending in “b”.

The configuration of first base plate 104 a is defined with reference toa horizontal reference line X and a vertical center reference line Y,provided in FIG. 4. The first base plate 104 a is a generally triangularthin plate having first and second side surfaces 129 a, 131 a separatedby an edge described herein.

A top 128 a of the first base plate 104 a is provided at theintersection of the horizontal reference line X and the vertical centerreference line Y. A bottom 130 a of the first base plate 104 a isprovided at a predetermined distance below the top 128 a, for example7.688 inches below. A first reference point A is provided at apredetermined distance below the top 128 a, for example 1.125 inchesbelow, along the reference line Y. A second reference point B isprovided at a predetermined distance below the top 128 a, for example2.250 inches below, along the reference line Y, and is spaced apart fromand below reference point A. A third reference point C is provided at apredetermined distance below the top 128 a, for example 3.875 inchesbelow, along the reference line Y, and is spaced apart from and belowreference point B. A fourth reference point D is provided at apredetermined distance below the reference line X, for example 3.604inches below, and at a predetermined distance to the left of referenceline Y, for example 1.797 inches to the left. A fifth reference point Eis provided at a predetermined distance below the reference line X, forexample 4.104 inches below, and at a predetermined distance to the leftof reference line Y, for example 3.172 inches to the left, and fallsoutside of the physical surface of the first base plate 104 a. A sixthreference point F is provided at a predetermined distance below thereference line X, for example 5.409 inches below, and at a predetermineddistance to the left of reference line Y, for example 2.387 inches tothe left. A seventh reference point G is provided at a predetermineddistance below the reference line X, for example 6.438 inches below, andat a predetermined distance to the left of reference line Y, for example0.563 inches to the left. An eighth reference point H is provided at apredetermined distance below the reference line X, for exampleapproximately 1.75 inches below, and at a predetermined distance to theleft of reference line Y, for example approximately 0.625 inches to theleft. Reference points E is provided outside of the perimeter of thefirst base plate 104 a, whereas reference points A, B, C, D, F, G, H areprovided inside of the perimeter of the first base plate 104 a.

The left side of the first base plate 104 a (everything to the left ofthe reference line Y as viewed in FIG. 3) is described, with theunderstanding that the right side of the first base plate 104 a(everything to the right of the reference line Y as viewed in FIG. 3) isthe mirror image. As such, the edges, apertures and reference points onthe right side are not described and are denoted with a prime.

From the top 128 a, a first edge portion 132 a is formed as an arc aboutreference point A at a predetermined radius, for example at a radius of1.125 inches. Thus, the first edge portion 132 a curves downwardly andto the left of reference line Y. A third edge portion 136 a is formed asan arc about reference point D at a predetermined radius, for example ata radius of 0.687 inches. A second edge portion 134 a is formed as aline which is tangent to both the first edge portion 132 a and the thirdedge portion 136 a. Thus, the second edge portion 134 a extendsdownwardly and to the left from the first edge portion 132 a to thethird edge portion 136 a, and the third edge portion 136 a curvesdownwardly and to the left from the second edge portion 134 a. A fifthedge portion 140 a is formed as an arc about reference point E at apredetermined radius, for example at a radius of 0.688 inches. A fourthedge portion 138 a is formed as a line which is tangent to both thethird edge portion 136 a and the fifth edge portion 140 a. Thus, thefourth edge portion 138 a extends downwardly and to the left from thethird edge portion 136 a to the fifth edge portion 140 a, and the fifthedge portion 140 a curves downwardly and to the left from the fourthedge portion 138 a. A seventh edge portion 144 a is formed as an arcabout reference point F at a predetermined radius, for example at aradius of 0.687 inches. A sixth edge portion 142 a is formed as a linewhich is tangent to both the fifth edge portion 140 a and the seventhedge portion 144 a. Thus, the sixth edge portion 142 a extendsdownwardly and to the left from the fifth edge portion 140 a to theseventh edge portion 144 a, and the seventh edge portion 144 a curvesdownwardly and to the left from the sixth edge portion 142 a to a leftend 146 a, which is the furthermost left point along the perimeter ofthe first base plate 104 a from reference line Y, and further curvesdownwardly and to the right from the left end 146 a. A ninth edgeportion 150 a is formed as an arc about reference point G at apredetermined radius, for example at a radius of 1.250 inches. An eighthedge portion 148 a is formed as a line which is tangent to both theseventh edge portion 144 a and the ninth edge portion 150 a. Thus, theeighth edge portion 148 a extends downwardly and to the right from theseventh edge portion 144 a to the ninth edge portion 150 a, and theninth edge portion 150 a curves downwardly and to the right from theeighth edge portion 148 a. A tenth edge portion 152 a is formed as aline which is tangent to the ninth edge portion 150 a and which isparallel to the reference line X. Thus, the tenth edge portion 152 aextends straight to the right from the ninth edge portion 150 a to thebottom 130 a A first aperture 180 a is formed through the first baseportion 104 a and extends from the first surface 129 a to the secondsurface 131 a. The first aperture 180 a is generally shaped like anhourglass and includes a first section 182 a, a second section 184 a,and a third connecting section 186 a which connects the first section182 a to the second section 184 a. The first, second and third sections182 a, 184 a, 186 a are all illustrated as being bisected by thereference line Y such that half of the first, second and third sections182 a, 184 a, 186 a are provided on the left side of the first baseportion 104 a and such that the other half of the first, second andthird sections 182 a, 184 a, 186 a are provided on the right side of thefirst base portion 104 a.

The first portion 182 a is formed by a circle with a predeterminedradius defined about reference point A, for example a radius of 0.544inches. The second portion 184 a is formed by a circle with apredetermined radius defined about reference point B, for example aradius of 0.544 inches. The circles defining the first and secondportions 182 a, 184 a are tangential to one another at a point which ison the same horizontal plane as reference points H and H′. Theconnecting portion 186 a is defined by edges of the first aperture 180 aformed at a predetermined radius about reference points H and H′,respectively, for example at a radius of 0.375 inches, such that thefirst aperture 180 a is relatively hourglass shaped.

A second aperture 188 a is formed through the first base portion 104 aand extends from the first surface 129 a to the second surface 113 a.The second aperture 188 a is formed by a circle with a predeterminedradius defined about reference point C, for example with a radius of0.29 inches. The second aperture 188 a is illustrated as being bisectedby the reference line Y such that half of the second aperture 188 a isprovided on the left side of the first base portion 104 a and such thatthe other half of the second aperture 188 a is provided on the rightside of the first base portion 104 a.

A third aperture 190 a is formed through the first base portion 104 aand extends from the first surface 129 a to the second surface 131 a.The third aperture 190 a is formed by a circle with a predeterminedradius defined about reference point G, for example with a radius of0.29 inches.

A fourth aperture 190 a′ is formed through the first base plate 104 aand extends from the first surface 129 a to the second surface 131 a.The fourth aperture 190 a′ is formed on the right side of the first baseplate 104 a and is the mirror image of the third aperture 190 a, whichis formed on the left side of the first base plate 104 a.

FIGS. 5 and 6 illustrate the first secondary base plate 106 a, which ispreferably formed of a forged, cast or fabricated metal. The firstsecondary base plate 106 a is identical in shape and configuration tothe second secondary base plate 106 b. As such, only the first secondarybase plate 106 a is described with the understanding that thedescription of the second secondary base plate 106 a would be identical.The elements of the first secondary base plate 106 a will have referencenumerals ending in “a”. As such, it is to be understood that theelements of the second base plate 106 b will have like referencenumerals ending in “b”.

The configuration of the first secondary base plate 106 a is definedwith reference to a horizontal reference line X and a vertical centerreference line Y, provided in FIG. 6. The first secondary base plate 106a is a generally triangular thin plate having first and second sidesurfaces 195 a, 197 a separated by an edge described herein.

A top 194 a of the secondary base plate 106 a is provided at theintersection of the horizontal reference line X and the vertical centerreference line Y. A bottom 196 a of the secondary base plate 106 a isprovided at a predetermined distance below the top 194 a, for example3.75 inches below. A first reference point A is provided at apredetermined distance below the top 194 a, for example 0.563 inches,along the reference line Y. A second reference point B is provided at apredetermined distance below the reference line X, for example 2.169inches below, and at a predetermined distance to the left of referenceY, for example 0.281 inches. A third reference point C is provided at apredetermined distance below the reference line X, for example 3.125inches below, and at a predetermined distance to the left of referenceY, for example 0.563 inches. Reference points A, B and C are allprovided inside the perimeter of the first secondary base plate 106 a.

The left side of the first secondary base plate 106 a (everything to theleft of the reference line Y as viewed in FIG. 6) is described, with theunderstanding that the right side of the first secondary base plate 106a (everything to the right of the reference line Y as viewed in FIG. 6)is the mirror image. As such, the edges, apertures and reference pointson the right side are not described and are denoted with a prime.

From the top 194 a, a first edge portion 198 a is formed as an arc aboutreference point A at a predetermined radius, for example at a radius of0.562 inches. Thus, the first edge portion 198 a curves downwardly andto the left of reference line Y. A third edge portion 202 a is formed asan arc about reference point B at a predetermined radius, for example ata radius of 1.5 inches. A second edge portion 200 a is formed as a linewhich is tangent to both the first edge portion 198 a and the third edgeportion 202 a. Thus, the second edge portion 200 a extends downwardlyand to the left from the first edge portion 198 a to the third edgeportion 202 a, and the third edge portion 202 a curves downwardly and tothe left from the second edge portion 200 a to a left end 204 a, whichis the furthermost left point along the perimeter of the first secondarybase plate 106 a from reference line Y, and further curves downwardlyand to the right from the left end 204 a. A fifth edge portion 208 a isformed as an arc about reference point C at a predetermined radius, forexample at a radius of 0.625 inches. A fourth edge portion 206 a isformed as a line which is tangent to both the third edge portion 202 aand the fifth edge portion 208 a. Thus, the fourth edge portion 206 aextends downwardly and to the right from the third edge portion 202 a tothe fifth edge portion 208 a, and the fifth edge portion 208 a curvesdownwardly and to the right from the fourth edge portion 206 a. A sixthedge portion 210 a is formed as a line which is tangent to the fifthedge portion 208 a and which is parallel to the reference line X. Thus,the sixth edge portion 210 a extends straight to the right from thefifth edge portion 208 a to the bottom 196 a A first aperture 230 a isformed through the first secondary base plate 106 a and extends from thefirst surface 195 a to the second surface 197 a. The first aperture 230a is formed by a circle with a predetermined radius defined aboutreference point A, for example with a radius of 0.29 inches. The firstaperture 230 a is illustrated as being bisected by the reference line Ysuch that half of the first aperture 230 a is provided on the left sideof the first secondary base plate 106 a and such that the other half ofthe first aperture 230 a is provided on the right side of the firstsecondary base plate 106 a.

A second aperture 232 a is formed through the first secondary base plate106 a and extends from the first surface 195 a to the second surface 197a. The second aperture 232 a is formed by a circle with a predeterminedradius defined about reference point C, for example with a radius of0.29 inches.

A third aperture 232 a′ is formed through the first secondary base plate106 a and extends from the first surface 195 a to the second surface 197a. The third aperture 232 a′ is formed on the right side of the firstsecondary base plate 106 a and is the mirror image of the secondaperture 232 a, which is formed on the left side of the first secondarybase plate 106 a.

FIGS. 7 and 8 illustrate the first equalizer arm 108 a, which ispreferably formed of a forged, cast or fabricated metal. The firstequalizer arm 108 a is identical in shape and configuration to thesecond equalizer arm 108 b. As such, only the first equalizer arm 108 ais described with the understanding that the description of the secondequalizer arm 108 b would be identical. The elements of the firstequalizer arm 108 a will have reference numerals ending in “a”. As such,it is to be understood that the elements of the second equalizer arm 108b will have like reference numerals ending in “b”.

The configuration of the first equalizer arm 108 a is defined withreference to a horizontal reference line X and a vertical centerreference line Y, provided in FIG. 8. The first equalizer arm 108 a is athin plate having first and second side surfaces 238 a, 239 a separatedby an edge described herein.

A bottom 236 a of the first equalizer arm 108 a is provided at theintersection of the horizontal reference line X and the vertical centerreference line Y. A first reference point A is provided at apredetermined distance above the bottom 236 a, for example 2.173 inchesabove. A second reference point B is provided at a predetermineddistance above the reference line X, for example 1.5 inches above, andat a predetermined distance to the left of reference line Y, for example1.75 inches. Reference points A and B are provided outside of theperimeter of the first equalizer arm 108 a.

The left side of the first equalizer arm 108 a (everything to the leftof the reference line Y as viewed in FIG. 8) is described, with theunderstanding that the right side of the first equalizer arm 108 a(everything to the right of the reference line Y as viewed in FIG. 8) isthe mirror image. As such, the edges and reference points on the rightside are not described and are denoted with a prime.

From the bottom 236 a, a first edge portion 240 a extends straight tothe left of reference line Y, along reference line X, for a predeterminedistance, for example 1.504 inches. A left end 244 a of the firstequalizer arm 108 a, which is the furthermost left point along theperimeter of the first equalizer arm 108 a from reference line Y, isprovided at a predetermined distance from both the reference line X andthe reference line Y, for example 0.612 inches above reference line Xand 2.794 inches to the left of reference line Y. A second edge portion242 a extends straight upwardly and to the left of reference line Y fromthe first edge portion 240 a to the left end 244 a. A top left end 248 aof the first equalizer arm 108 a is provided at a predetermined distancefrom both the reference line X and the reference line Y, for example1.375 inches above reference line X and 2.432 inches to the left ofreference line Y. From the left end 244 a, a third edge portion 246 aextends straight upwardly and to the right to the top left end 248 a. Afifth edge portion 252 a is formed as an arc about reference point B ata predetermined radius, for example at a radius of 0.535 inches. Fromthe top left end 248 a, a fourth edge portion 250 a extends straight tothe right toward the reference line Y and parallel to the reference lineX, to an end of the fifth edge portion 252 a. A seventh edge portion 256a is formed as an arc about reference point A at a predetermined radius,for example at a radius of 1.338 inches. A sixth edge portion 254 aextends parallel to the reference line X and is co-planar with thefourth edge portion 250 a. The sixth edge portion 254 a connects thefifth edge portion 252 a to the seventh edge portion 256 a. The fifthedge portion 252 a thus curves downwardly and to the right from thefourth edge portion 250 a and then upwardly and to the right to thesixth edge portion 254 a. The seventh edge portion 256 a thus curvesdownwardly and to the right from the sixth edge portion 254 a to thereference line Y, to a predetermined position above the bottom 236 a,for example 0.835 inches above.

Attention is directed to FIGS. 9 and 10 which illustrate the first lowershock plate 110 a, which is preferably formed of a forged, cast orfabricated metal. The first lower shock plate 110 a is identical inshape and configuration to the second lower shock plate 110 b. As such,only the first lower shock plate 110 a is described with theunderstanding that the description of the second lower shock plate 100 bwould be identical. The elements of the first lower shock plate 110 awill have reference numerals ending in “a”. As such, it is to beunderstood that the elements of the second lower shock plate 110 b willhave like reference numerals ending in “b”.

The first lower shock plate 110 a is a thin plate which is curved from afirst end 274 a thereof to a second end 276 a thereof. The first lowershock plate 110 a has a generally uniform predetermined thickness fromthe first end 274 a to the second end 276 a, for example a thickness of0.125 inches, such that the first lower shock plate 110 a has an innersurface 278 a, an outer surface 279 a, a first side 280 a, and a secondside 281 a. The inner surface 278 a is formed as an arc about referencepoint A, as illustrated in FIG. 10, at a predetermined radius, forexample at a radius of 1.188 inches. The first and second ends 274 a,276 a are provided at a predetermined angle to one another relative tothe reference point A, for example an angle of 145 degrees. The firstand second ends 274 a, 276 a are provided at a predetermined lineardistance to one another, for example a distance of 1.563 inches.

Attention is directed to FIGS. 11 and 12 which illustrate the firstupper shock plate 112 a, which is preferably formed of a forged, cast orfabricated metal. The first upper shock plate 112 a is identical inshape and configuration to the second upper shock plate 112 b. As such,only the first upper shock plate 112 a is described with theunderstanding that the description of the second upper shock plate 112 bwould be identical. The elements of the first upper shock plate 112 awill have reference numerals ending in “a”. As such, it is to beunderstood that the elements of the second upper shock plate 112 b willhave like reference numerals ending in “b”.

The first upper shock plate 112 a is a thin plate which is curved from afirst end 282 a thereof to a second end 284 a thereof. The first uppershock plate 112 a has a generally uniform predetermined thickness fromthe first end 282 a to the second end 284 a, for example a thickness of0.125 inches, such that the first upper shock plate 112 a has an innersurface 286 a, an outer surface 287 a, a first side 288 a, and a secondside 289 a. The inner surface 286 a is formed as an arc about referencepoint A, as illustrated in FIG. 12, at a predetermined radius, forexample at a radius of 1.188 inches. The first and second ends 282 a,284 a are provided at a predetermined angle to one another relative tothe reference point A, for example an angle of 160 degrees. The firstand second ends 282 a, 284 a are provided at a predetermined lineardistance to one another, for example a distance of 1.625 inches.

FIGS. 13 and 14 illustrate the reinforcement plate 114, which ispreferably formed of a forged, cast or fabricated metal. Theconfiguration of the reinforcement plate 114 is defined with referenceto a horizontal reference line X and a vertical center reference line Y,provided in FIG. 14. The reinforcement plate 114 is a generally T-shapedthin plate having first and second side surfaces 305, 307 separated byan edge described herein.

A first reference point A is provided at a predetermined distance belowthe reference line X, for example 0.75 inches below, and along thereference line Y. A second reference point B is provided at apredetermined distance below the reference line X, for example 1.954inches below, and at a predetermined distance to the left of referenceline Y, for example 4.23 inches. Reference point B is provided outsideof the perimeter of the reinforcement plate 114, whereas reference pointA is provided inside of the perimeter of the reinforcement plate 114.

The left side of the reinforcement plate 114 (everything to the left ofthe reference line Y as viewed in FIG. 14) is described, with theunderstanding that the right side of the reinforcement plate 114(everything to the right of the reference line Y as viewed in FIG. 14)is the mirror image. As such, the edges and reference point on the rightside are not described and are denoted with a prime.

From the intersection of the reference lines X and Y, a first edgeportion 290 extends straight to the left of reference line Y, along thereference line X, for a predetermined distance, for example 1.875inches. A second edge portion 292 extends straight downwardly and to theleft from the first edge portion 290 at a predetermined angle, forinstance forty-five degrees, to a top end 294 of a third edge portion296. The third edge portion 296 is parallel to the reference line Y andis provided at a predetermined distance to the left of reference line Y,for example 2.375 inches. A fifth edge portion 300, which is parallel tothe reference line X, extends straight to the left from the referenceline Y and is provided at a predetermined distance below the referenceline X, for example 2.5 inches below. A fourth edge portion 298 isformed as an arc about reference point B at a predetermined radius, forexample 1.338 inches. The fourth edge portion 298 curves from a bottomend 295 of the third edge portion 296 to a left end 299 of the fifthedge portion 300.

An aperture 306 is formed through the reinforcement plate 114 andextends from the first side surface 305 to the second side surface 307.The aperture 306 is formed by a circle with a predetermined radiusdefined about reference point A, for example with a radius of 0.5625inches. The aperture 306 is illustrated as being bisected by thereference line Y such that half of the aperture 306 is provided on theleft side of the reinforcement plate 114 and such that the other half ofthe aperture 306 is provided on the right side of the reinforcementplate 114.

FIG. 15 illustrates the first shock absorber 116 a. The first shockabsorber 116 a is identical in shape and configuration to the secondshock absorber 116 b. As such, only the first shock absorber 116 a isdescribed with the understanding that the description of the secondshock absorber 116 b would be identical. The elements of the first shockabsorber 116 a will have reference numerals ending in “a”. As such, itis to be understood that the elements of the second shock absorber 116 bwill have like reference numerals ending in “b”.

The first shock absorber 116 a is preferably in the form of acylindrical puck or disk and made of TORSILASTIC® rubber. The firstshock absorber 116 a has a cylindrical outer surface 117 a providedbetween a first end surface 118 a and a second end surface (not shown).An aperture 307 a is provided through the first shock absorber 116 afrom the first end surface 118 a to the second end surface. In use, theouter surface 117 a is positioned between the inner surfaces 278 a, 286a of the first lower shock plate 110 a and the first upper shock plate112 a, respectively and, therefore, has a circumference which iscorrespondingly shaped to the first lower and upper shock plates 110,112. For example, the outer surface 117 a is formed at a radius ofapproximately 1.188 inches, which is the radius at which the innersurfaces 278 a, 286 a of the first lower and upper shock plates 111 a,112 a, respectively, are formed.

FIGS. 16 and 17 illustrate the first upper pivot tube 119 a, which ispreferably formed of a forged, cast or fabricated metal. The first upperpivot tube 119 a is identical in shape and configuration to the second,third and fourth upper pivot tubes 119 b, 119 c, 119 d. As such, onlythe first upper pivot tube 119 a is described with the understandingthat the description of the second, third and fourth upper pivot tubes119 b, 119 c, 119 d would be identical. The elements of the first upperpivot tube 119 a will have reference numerals ending in “a”. As such, itis to be understood that the elements of the second upper pivot tube 119b will have like reference numerals ending in “b”; the elements of thethird upper pivot tube 119 c will have like reference numerals ending in“c”; and the elements of the fourth upper pivot tube 119 d will havelike reference numerals ending in “d”.

The first upper pivot tube 119 a has a first end 308 a and a second end310 a. In a preferred embodiment, a distance from the first end 308 a tothe second end 310 a is approximately 1.75 inches. The first upper pivottube 119 a is formed of an outer tube 312 a and an inner tube or bushing314 a. The outer tube 312 a extends from the first end 308 a to thesecond end 310 a and has an aperture 316 a which extends therethroughfrom the first end 308 a to the second end 310 a. The outer tube 312 athus has an outer surface 318 a and an inner surface (not shown). In apreferred embodiment, the outer tube 312 a has an outer diameter ofapproximately 1.07 inches and an inner diameter of approximately 0.75inches. The inner tube or bushing 314 a is positioned within theaperture 316 a of the outer tube 312 a and extends from the first end308 a to the second end 310 a. The inner tube or bushing 314 a definesan aperture 320 a which extends therethrough from the first end 308 a tothe second end 310 a. The inner tube 314 a thus has an outer surface(not shown) and an inner surface 322 a In a preferred embodiment, theinner tube 314 a has an outer diameter of approximately 0.75 inches andan inner diameter of approximately 0.565 inches. The outer surface ofthe inner tube 314 a is configured and sized to snugly fit against theinner surface of the outer tube 312 a.

FIGS. 18 and 19 illustrate the first lower pivot tube 120 a, which ispreferably formed of a forged, cast or fabricated metal. The first lowerpivot tube 120 a is identical in shape and configuration to the secondlower pivot tube 120 b. As such, only the first lower pivot tube 120 ais described with the understanding that the description of the secondlower pivot tube 120 b would be identical. The elements of the firstlower pivot tube 120 a will have reference numerals ending in “a”. Assuch, it is to be understood that the elements of the second lower pivottube 120 b will have like reference numerals ending in “b”.

The first lower pivot tube 120 a has a first end 324 a and a second end326 a. A distance from the first end 324 a to the second end 326 a ispredetermined, for example approximately 1.563 inches. The first lowerpivot tube 120 a is formed of an outer tube 328 a and an inner tube orbushing 330 a. The outer tube 328 a extends from the first end 324 a tothe second end 326 a and has an aperture 332 a which extendstherethrough from the first end 324 a to the second end 326 a. The outertube 328 a thus has an outer surface 334 a and an inner surface (notshown). The outer tube 328 a has a predetermined outer diameter, forexample approximately 1.07 inches, and a predetermined inner diameter,for example approximately 0.75 inches. The inner tube or bushing 330 ais positioned within the aperture 332 a of the outer tube 328 a andextends from the first end 324 a to the second end 326 a. The inner tubeor bushing 330 a defines an aperture 336 a which extends therethroughfrom the first end 324 a to the second end 326 a. The inner tube 330 athus has an outer surface (not shown) and an inner surface 338 a. Theinner tube 330 a has a predetermined outer diameter, for exampleapproximately 0.75 inches, and a predetermined inner diameter, forexample approximately 0.565 inches. The outer surface of the inner tube330 a is configured and sized to snugly fit against the inner surface ofthe outer tube 328 a.

FIG. 20 illustrates the first fastening member 122 a. The firstfastening member 122 a is identical in shape and configuration to thesecond and third fastening members 122 b, 122 c. As such, only the firstfastening member 122 a is described with the understanding that thedescription of the second and third fastening members 122 b, 122 c wouldbe identical. The elements of the first fastening member 122 a will havereference numerals ending in “a”. As such, it is to be understood thatthe elements of the second fastening member 122 b will have likereference numerals ending in “b” and the elements of the third fasteningmember 122 c will have like reference numerals ending in “c”.

The first fastening member 122 a is preferably a bolt having an enlargedhead portion 340 a, a first shaft portion 342 a, and a second shaftportion 344 a. The enlarged head portion 340 a preferably is a hex-head,but other shapes are within the scope of the invention. The first shaftportion 342 a extends from the enlarged head portion 340 a and ispreferably cylindrical. The second shaft portion 344 a extends from thefirst shaft portion 342 a, such that the first shaft portion 342 a ispositioned between the enlarged head portion 340 a and the second shaftportion 344 a, and is preferably cylindrical and externally threaded.The second shaft portion 344 a preferably has a predetermined outerdiameter which is smaller than a predetermined outer diameter of thefirst shaft portion 342 a such that a shoulder 346 a is provided betweenthe first and second shaft portions 342 a, 344 a. The predeterminedouter diameter of the first shaft portion 342 a is preferably smallerthan a predetermined outer diameter of the enlarged head portion 340 asuch that a shoulder 348 a is provided between the enlarged head portion340 a and the first shaft portion 342 a.

FIG. 21 illustrates the first securing member 124 a. The first securingmember 124 a is identical in shape and configuration to the second andthird securing members 124 b, 124 c. As such, only the first securingmember 124 a is described with the understanding that the description ofthe second and third securing members 124 b, 124 c would be identical.The elements of the first securing member 124 a will have referencenumerals ending in “a”. As such, it is to be understood that theelements of the second securing member 124 b will have like referencenumerals ending in “b” and the elements of the third securing member 124c will have like reference numerals ending in “c”.

The first securing member 124 a preferably includes a conventional nut350 a secured to a conventional washer 352 a. The nut 350 a preferablyhas a hex-head. The nut 350 a and the washer 352 a have an aperture 354a extending therethrough. The aperture 354 a defines an aperture wallwhich is preferably at least partially threaded.

FIGS. 22 and 23 illustrate the base or shock spacer 126, which ispreferably formed of a forged, cast or fabricated metal. The base orshock spacer 126 has a first end 356 and a second end 358. A distancefrom the first end 356 to the second end 358 is predetermined, forexample approximately 1.625 inches. The base or shock spacer 126 isformed as a tube and has an aperture 360 which extends therethrough froma first end 356 to a second end 358. The base or shock spacer 126 thushas an outer surface 362 and an inner surface 364. An outer diameter ofthe base or shock spacer 126 at the outer surface 362 thereof ispredetermined, for example approximately 1.07 inches, and an innerdiameter of the base or shock spacer 126 at the inner surface 364thereof is predetermined, for example approximately 0.75 inches.

FIGS. 2 and 24-38 illustrate the construction of the equalizer 100 aloneand in conjunction with the suspension system 102, as well as thefunction of the equalizer 100 with the suspension system 102.

The equalizer 100 is constructed by forming first and second equalizerarm assemblies 366, 368. The configuration of the first equalizer armassembly 366 is illustrated in FIGS. 24-26. The first equalizer armassembly 366 includes the first equalizer arm 108 a, the first lowershock plate 110 a, the first upper pivot tube 119 a, and the first lowerpivot tube 120 a.

The outer surface 318 a of the outer tube 312 a of the first upper pivottube 119 a is positioned against the fifth edge portion 252 a of thefirst equalizer arm 108 a, such that the first end 308 a of the firstupper pivot tube 119 a extends outwardly from the first surface 238 a ofthe first equalizer arm 108 a and such that the second end 310 a of thefirst upper pivot tube 119 a extends outwardly from the second surface239 a of the first equalizer arm 108 a. The outer surface 318 a of theouter tube 312 a of the first upper pivot tube 119 a is fixedly securedto the first equalizer arm 108 a, preferably by welding.

The outer surface 334 a of the outer tube 328 a of the first lower pivottube 120 a is positioned against the fifth edge portion 252 a′ of thefirst equalizer arm 108 a, such that the first end 324 a of the firstlower pivot tube 120 a extends outwardly from the first surface 238 a ofthe first equalizer arm 108 a and such that the second end 326 a of thefirst lower pivot tube 120 a extends outwardly from the second surface239 a of the first equalizer arm 108 a. The first end 324 a is providedcloser to the first surface 238 a of the first equalizer arm 108 a thanis the first end 308 a of the first upper pivot tube 119 a, and thesecond end 326 a is provided closer to the second surface 239 a of thefirst equalizer arm 108 a than is the second end 310 a of the firstupper pivot tube 119 a. The outer surface 334 a of the outer tube 328 aof the first lower pivot tube 120 a is fixedly secured to the firstequalizer arm 108 a, preferably by welding.

The outer surface 279 a of the first lower shock plate 110 a ispositioned against the seventh edge portions 256 a, 256 a′ of the firstequalizer arm 108 a, such that the first side 280 a of the first lowershock plate 110 a extends outwardly from the first surface 238 a of thefirst equalizer arm 108 a and such that the second side 281 a of thefirst lower shock plate 110 a extends outwardly from the second surface239 a of the first equalizer arm 108 a. The first side 280 a issubstantially flush with the first end 324 a of the first lower pivottube 120 a, and the second side 282 a is substantially flush with thesecond end 326 a of the first lower pivot tube 120 a. The outer surface279 a of the first lower shock plate 110 a is fixedly secured to thefirst equalizer arm 108 a, preferably by welding. The outer surface 279a of the first lower shock plate 110 a, proximate to the first end 274 athereof, faces, and may abut against, the outer surface 318 a of theouter tube 312 a of the first upper pivot tube 119 a. The outer surface279 a of the first lower shock plate 110 a, proximate to the second end276 a thereof, faces, and may abut against, the outer surface 334 a ofthe outer tube 328 a of the first lower pivot tube 120 a.

The second equalizer arm assembly 368 includes the second equalizer arm108 b, the second lower shock plate 110 b, the second upper pivot tube119 b, and the second lower pivot tube 120 b. The configuration of thesecond equalizer arm assembly 368 is identical to the configuration ofthe first equalizer arm assembly 366, illustrated in FIGS. 24-26, exceptthat the outer surface 318 b of the outer tube 312 b of the second upperpivot tube 119 b is positioned against the fifth edge portion 252 b′ ofthe second equalizer arm 108 b, as opposed to the fifth edge portion 252b, and the outer surface 334 b of the outer tube 328 b of the firstlower pivot tube 120 b is positioned against the fifth edge portion 252b′ of the second equalizer arm 108 b, as opposed to the fifth edgeportion 252 b′.

Attention is invited to FIGS. 2 and 27-36. The equalizer 100 is furtherconstructed by forming a reinforcement plate assembly 370. Thereinforcement plate assembly 370 includes the reinforcement plate 114,the shock spacer 126, and the first and second upper shock plates 112 a,112 b.

The shock spacer 126 is inserted through the aperture 306 of thereinforcement plate 114 such that the first end 356 of the shock spacer126 extends outwardly from the first surface 305 of the reinforcementplate 114 and such that the second end 358 of the shock spacer 126extends outwardly from the second surface 307 of the reinforcement plate114. The second end 358 preferably extends further outwardly from thesecond surface 307 than does the first end 356 from the first surface305. The outer surface 362 is preferably generally positioned against awall defined by the aperture 306, and the outer surface 362 is fixedlysecured to the reinforcement plate 114, preferably by welding. The shockspacer 126 spaces the reinforcement plate 114 from the first and secondbase plates 104 a, 104 b The outer surface 287 a of the first uppershock plate 112 a is positioned against the fourth edge portion 298 ofthe reinforcement plate 114, such that the first side 288 a of the firstupper shock plate 112 a extends outwardly from the first surface 305 ofthe reinforcement plate 114 and such that the second side 289 a of thefirst upper shock plate 112 a extends outwardly from the second surface307 of the reinforcement plate 114. The outer surface 287 a of the firstupper shock plate 112 a is fixedly secured to the reinforcement plate114, preferably by welding. The second side 289 a preferably extendsfurther outwardly from the second surface 307 than does the first side288 a from the first surface 305. The first side 288 a is substantiallyplanar with the first end 356 of the shock spacer 126, and the secondside 289 a is substantially planar with the second end 358 of the shockspacer 126.

The outer surface 287 b of the second upper shock plate 112 b ispositioned against the fourth edge portion 298′ of the reinforcementplate 114, such that the first side 288 b of the second upper shockplate 112 b extends outwardly from the first surface 305 of thereinforcement plate 114 and such that the second side 289 b of thesecond upper shock plate 112 b extends outwardly from the second surface307 of the reinforcement plate 114. The outer surface 287 b of thesecond upper shock plate 112 b is fixedly secured to the reinforcementplate 114, preferably by welding. The second side 289 b preferablyextends further outwardly from the second surface 307 than does thefirst side 288 b from the first surface 305. The first side 288 b issubstantially planar with the first end 356 of the shock spacer 126, andthe second side 289 b is substantially planar with the second end 358 ofthe shock spacer 126.

The reinforcement plate assembly 370 is positioned against the firstsurface 129 b of the second base plate 104 b such that the second end358 of the shock spacer 126, and the second sides 289 a, 289 b of thefirst and second upper shock plates 112 a, 112 b, abut against the firstsurface 129 b of the second base plate 104 b. The aperture 360 of theshock spacer 126 is aligned with the second aperture 188 b of the secondbase plate 104 b. The reinforcement plate assembly 370 is fixedlysecured to the first surface 129 b of the second plate 104 b, preferablyby welding the outer surface 362 of the shock spacer 126 to the firstsurface 129 b of the second plate 104 b, by welding the outer surface287 a of the first upper shock plate 112 a to the first surface 129 b,proximate to the fourth edge portion 138 b thereof, and by welding theouter surface 287 b of the second upper shock plate 112 b to the firstsurface 129 b, proximate to the fourth edge portion 138 b′ thereof.

The third upper pivot tube 119 c is positioned within the first portion182 b of the first aperture 180 b of the second base plate 104 b suchthat the second end 310 c of the third upper pivot tube 119 c issubstantially flush with the second surface 131 b of the second baseplate 104 b. The outer surface 318 c of the outer tube 312 c of thethird upper pivot tube 119 c is fixedly secured to the first surface 129b of the second base plate 104 b, preferably by welding.

The fourth upper pivot tube 119 d is positioned within the secondportion 184 b of the first aperture 180 b of the second base plate 104 bsuch that the second end 310 d of the fourth upper pivot tube 119 d issubstantially flush with the second surface 131 b of the second baseplate 104 b. The outer surface 318 d of the outer tube 312 d of thefourth upper pivot tube 119 d is fixedly secured to the first surface129 b of the second base plate 104 b, and to the outer surface 318 c ofthe outer tube 312 c of the third upper pivot tube 119 c, preferably bywelding.

The first equalizer arm assembly 366 is positioned such that the secondend 326 a of the first lower pivot tube 120 a faces the first surface129 b of the second base plate 104 b. The aperture 336 a of the firstlower pivot tube 120 a is in alignment with the aperture 190 b providedthrough the second base plate 104 b. The inner surfaces 278 a, 286 a ofthe first lower and upper shock plates 110 a, 112 a face one another.The first shock absorber 116 a is positioned between the inner surfaces278 a, 286 a of the first lower and upper shock plates 110 a, 112 a suchthat the outer surface 117 a of the first shock absorber 116 a generallyabuts against or faces the inner surfaces 278 a, 286 a of the firstlower and upper shock plates 110 a, 112 a. The first shock absorber 116a is held in place between the first lower and upper shock plates 110 a,112 a. The first end 274 a of the first lower shock plate 110 a isspaced from the first end 282 a of the first upper shock plate 112 a.The second end 276 a of the first lower shock plate 110 a is spaced fromthe second end 284 a of the first upper shock plate 112 a.

The second equalizer arm assembly 368 is positioned such that the secondend 326 b of the second lower pivot tube 120 b faces the first surface129 b of the second base plate 104 b. The aperture 336 b of the secondlower pivot tube 120 b is in alignment with the aperture 192 b providedthrough the second base plate 104 b. The inner surfaces 278 b, 286 b ofthe second lower and upper shock plates 110 b, 112 b face one another.The second shock absorber 116 b is positioned between the inner surfaces278 b, 286 b of the second lower and upper shock plates 110 b, 112 bsuch that the outer surface 117 b of the second shock absorber 116 bgenerally abuts against or faces the inner surfaces 278 b, 286 b of thesecond lower and upper shock plates 110 b, 112 b. The second shockabsorber 116 b is held in place between the first lower and upper shockplates 110 b, 112 b. The first end 274 b of the second lower shock plate110 b is spaced from the first end 282 b of the second upper shock plate112 b. The second end 276 b of the second lower shock plate 110 b isspaced from the second end 284 b of the second upper shock plate 112 b.

The first base plate 104 a is positioned, as illustrated in FIG. 30,such that the first end 308 c of the third upper pivot tube 119 cextends into, from the second surface 131 a of the first base plate 104a, the first portion 182 a of the first aperture 180 a of the first baseplate 104 a; such that the first end 308 d of the fourth upper pivottube 119 d extends into, from the second surface 131 a of the first baseplate 104 a, the second portion 184 a of the first aperture 180 a of thefirst base plate 104 a; such that the first end 356 of the shock spacer126 faces the second surface 131 a of the first base plate 104 a, withthe aperture 360 of the shock spacer 126 being in alignment with thesecond aperture 188 a of the first base plate 104 a; such that the firstend 324 a of the first lower pivot tube 120 a faces the second surface131 a of the first base plate 104 a, with the aperture 336 a of thefirst lower pivot tube 120 a being in alignment with the third aperture190 a of the first base plate 104 a; such that the first end 324 b ofthe second lower pivot tube 120 b faces the second surface 131 a of thefirst base plate 104 a, with the aperture 336 b of the second lowerpivot tube 120 b being in alignment with the fourth aperture 190 a′ ofthe first base plate 104 a; such that the first sides 280 a, 280 b, 288a, 288 b of the first and second lower and upper shock plates 110 a, 110b, 112 a, 112 b, respectively, face the second surface 131 a of thefirst base plate 104 a; and such that the first surfaces 118 a, 118 b ofthe first and second shock absorbers 116 a, 116 b, respectively, facethe second surface 131 a of the first base plate 104 a.

As illustrated in FIG. 31, the second surface 197 a of the firstsecondary base plate 106 a is positioned against the first surface 129 aof the first base plate 104 a such that the first aperture 230 a of thefirst secondary base plate 106 a is in alignment with the secondaperture 188 a of the first base plate 104 a, the second aperture 232 aof the first secondary base plate 106 a is in alignment with the thirdaperture 190 a of the first base plate 104 a, and the third aperture 232a′ of the first secondary base plate 106 a is in alignment with thefourth aperture 192 a of the first base plate 104 a. The first secondarybase plate 106 a is fixedly secured to the first surface 129 a of thefirst base plate 104 a, preferably by welding.

Likewise, although not explicitly illustrated, the first surface 195 bof the second secondary base plate 106 b is positioned against thesecond surface 131 b of the second base plate 104 b such that the firstaperture 230 b of the second secondary base plate 106 b is in alignmentwith the second aperture 188 b of the second base plate 104 b, thesecond aperture 232 b of the second secondary base plate 106 b is inalignment with the third aperture 190 b of the second base plate 104 b,and the third aperture 232 b′ of the second secondary base plate 106 bis in alignment with the fourth aperture 190 b′ of the second base plate104 b. The second secondary base plate 106 b is fixedly secured to thesecond surface 131 b of the second base plate 104 b, preferably bywelding.

As best illustrated in FIG. 32, the first fastening member 122 a extendsthrough the first aperture 230 b of the second secondary base plate 106b, through the second aperture 188 b of the second base plate 104 b,through the aperture 360 of the shock spacer 126, through the secondaperture 188 a of the first base plate 104 a, and through the firstaperture 230 a of the first secondary base plate 106 a, such that theshoulder 348 a of the first fastening member 122 a abuts against thesecond surface 197 b of the second secondary base plate 106 b and atleast a portion of the threaded, second shaft portion 344 a of the firstfastening member 122 a extends beyond the first surface 195 a of thefirst secondary base plate 106 a. The first securing member 124 a isthreaded onto the threaded, second shaft portion 344 a of the firstfastening member 122 a such that the washer member 352 a is tightlypositioned against the first surface 195 a of the first secondary baseplate 106 a. The reinforcement plate assembly 370 is thus fixedlysecured to the first base plate 104 a by the first fastening andsecuring members 122 a, 124 a.

The second fastening member 122 b extends through the second aperture232 b of the second secondary base plate 106 b, through the thirdaperture 190 b of the second base plate 104 b, through the aperture 336a of the first lower pivot tube 120 a, through the third aperture 190 aof the first base plate 104 a, and through the second aperture 232 a ofthe first secondary base plate 106 a, such that the shoulder 348 b ofthe second fastening member 122 b abuts against the second surface 197 bof the second secondary base plate 106 b and at least a portion of thethreaded, second shaft portion 344 b of the second fastening member 122b extends beyond the first surface 195 a of the first secondary baseplate 106 a. The second securing member 124 b is threaded onto thethreaded, second shaft portion 344 b of the second fastening member 122b such that the washer member 352 b is tightly positioned against thefirst surface 195 a of the first secondary base plate 106 a.

The third fastening member 122 c extends through the third aperture 232b′ of the, second secondary base plate 106 b, through the fourthaperture 190 b′ of the second base plate 104 b, through the aperture 336b of the second lower pivot tube 120 b, through the fourth aperture 190a′ of the first base plate 104 a, and through the third aperture 232 a′of the first secondary base plate 106 a, such that the shoulder 348 c ofthe third fastening member 122 c abuts against the second surface 197 bof the second secondary base plate 106 b and at least a portion of thethreaded, second shaft portion 344 c of the third fastening member 122 cextends beyond the first surface 195 a of the first secondary base plate106 a. The third securing member 124 c is threaded onto the threaded,second shaft portion 344 c of the third fastening member 122 c such thatthe washer member 352 c is tightly positioned against the first surface195 a of the first secondary base plate 106 a. The first equalizer armassembly 366 is thus rotatably secured or pivotally mounted between thefirst and second base plates 104 a, 104 b by the second fastening andsecuring members 122 b, 124 b. The second equalizer arm assembly 368 isthus rotatably secured or pivotally mounted between the first and secondbase plates 104 a, 104 b by the third fastening and securing members 122c, 124 c.

The equalizer 100 is thus provided as illustrated in FIG. 32.

As illustrated in FIGS. 2, 33, 35 and 36, the equalizer 100 is securedto a center frame hangar 372 which depends from a frame 374 of a trailer(not shown). The center frame hangar 372 is generally U-shaped such thatit has a base portion 376 and first and second portions 378, 380 whichextend downwardly from opposite ends of the base portion 376. The baseportion 376 is fixedly secured to the frame 374 of the trailer by knownmeans, such as welding. The first extending portion 378 has an aperture382 extending therethrough proximate to a free end 384. The secondextending portion 380 has an aperture 386 extending therethroughproximate to a free end 388. The apertures 382, 386 are in alignmentwith one another and the free ends 384, 388 are preferably planar.

As illustrated in FIGS. 2, 33 and 35-38, the first and second baseplates 104 a, 104 b are positioned between the first and secondextending portions 378, 380 of the center frame hangar 372 such that thefirst surface 129 a of the first base plate 104 a faces the firstextending portion 378, and the second surface 131 b of the second baseplate 104 b faces the second extending portion 380. The second portion184 a of the first aperture 180 a of the first base plate 104 a is inalignment with the aperture 382 of the first extending portion 378 ofthe center frame hangar 372. Likewise, the second portion 184 b of thefirst aperture 180 b of the second base plate 104 b is in alignment withthe aperture 386 of the second extending portion 380 of the center framehangar 372. A fastening member 390, which may be identical to ordifferent from the fastening members 122 a, 122 b, 122 c can be insertedthrough the aperture 386 of the second extending portion 380 of thecenter frame hangar 372, through the second portion 184 b of the firstaperture 180 b of the second base plate 104 b, through the aperture 320d of the fourth upper pivot tube 119 d, through the second portion 184 aof the first aperture 180 a of the first base plate 104 a, and throughthe aperture 382 of the first extending portion 378 of the center framehangar 372. A securing member 392, which may be identical to ordifferent from the fastening members 124 a, 124 b, 124 c can then besecured to the fastening member 390 such that the equalizer 100 isrotatably secured or pivotally mounted between the first and secondextending portions 378, 380 of the center frame hangar 372 by thefastening and securing members 390, 392.

It should be noted that, alternatively, the equalizer 100 can also berotatably secured or pivotally mounted between the first and secondextending portions 378, 380 of the center frame hangar 372 by thefastening and securing members 390, 392, as illustrated in FIG. 34. InFIG. 34, the first portion 182 a of the first aperture 180 a of thefirst base plate 104 a is in alignment with the aperture 382 of thefirst extending portion 378 of the center frame hangar 372 and the firstportion 182 b of the first aperture 180 b of the second base plate 104 bis in alignment with the aperture 386 of the second extending portion380 of the center frame hangar 372. As such, the fastening member 390can be inserted through the aperture 386 of the second extending portion380 of the center frame hangar 372, through the first portion 182 b ofthe first aperture 180 b of the second base plate 104 b, through theaperture 320 c of the third upper pivot tube 119 c, through the firstportion 182 a of the first aperture 180 a of the first base plate 104 a,and through the aperture 382 of the first extending portion 378 of thecenter frame hangar 372. The securing member 392 can then be secured tothe fastening member 390.

Thus, the configuration of the equalizer 100 allows for two differentconnections to the center frame hangar 372 of the frame 374 of thetrailer depending on the desired position of the equalizer 100 relativeto the frame 374 of the trailer.

As illustrated in FIG. 2, the suspension system 102 includes theequalizer 100, a front leaf spring 394, a rear leaf spring 396, a frontshackle or link 398 and a rear shackle or link 400. As discussed above,the equalizer 100 is rotatably secured or pivotally mounted to thecenter frame hangar 372 of the frame 374 of the trailer, illustrated ata point J in FIG. 2. A first end 402 of the front shackle 398 isrotatably secured or pivotally mounted to the first equalizer armassembly 366, at a point K. The first end 402 of the front shackle 398is rotatably secured or pivotally mounted to the first equalizer armassembly 366 by a fastening member and a securing member. The fasteningmember extends through apertures of the front shackle 398 and theaperture 320 a of the first upper pivot tube 119 a. A first end 404 ofthe rear shackle 400 is rotatably secured or pivotally mounted to thesecond equalizer arm assembly 368, at a point L. The first end 404 ofthe rear shackle 400 is rotatably secured or pivotally mounted to thesecond equalizer arm assembly 368 by a fastening member and a securingmember. The fastening member extends through apertures of the rearshackle 400 and the aperture 320 b of the second upper pivot tube 119 b.The fastening members may be identical to or different from thefastening members 122 a, 122 b, 122 c. The securing members may beidentical to or different from the securing members 124 a, 124 b, 124 c.

A second end 406 of the front shackle 398 is rotatably secured orpivotally mounted to a rear end 408 of the front leaf spring 394 at apoint M. A front end 410 of the front leaf spring 394 is attached to afront frame hangar 411 of the frame 374 at a point N, as illustrated inFIG. 2, or can be directly attached to the frame 374 itself, dependingon the configuration of the frame 374.

A second end 412 of the rear shackle 400 is rotatably secured orpivotally mounted to a front end 414 of the rear leaf spring 396 at apoint P. A rear end 416 of the rear leaf spring 396 is attached to arear frame hangar 417 of the frame 374 at a point Q, as illustrated inFIG. 2, or can be directly attached to the frame 374 itself, dependingon the configuration of the frame 374.

A front axle 418 of the trailer is positioned on the forward leaf spring394 generally equidistantly between point M and point N. A rear axle 420is positioned on the rear leaf spring 396 generally equidistantlybetween point P and point Q.

It is to be understood that while only a single suspension system 102 isillustrated and described, it is typical to have one suspension system102 provided on both a left and a right side of a trailer. If more thantwo axles are provided on the trailer, it is to be understood that twoor more suspension systems 102 can be provided on both a left and aright side of the trailer.

Like the prior art suspension system 20 including the equalizer 22illustrated in FIG. 1, to the extent possible, road shock and vibrationsfrom tires (not shown) of the trailer, utilizing the suspension system102 including the equalizer 100 of the present invention, aretransferred to the front and rear axles 418, 420, and are absorbed bythe front and rear leaf springs 394, 396, respectively. Points J, N andQ are the contact points through which the road shock is passed to theframe 374. The equalizer 100 is included in the suspension system 102 inorder to equalize the weight on both the front and rear axles 418, 420as the tires pass over uneven terrain. For example, an upward motion ofthe front leaf spring 394 results in a downward motion of the rear leafspring 396.

As illustrated in FIGS. 37 and 38, the equalizer 100, unlike theequalizer 22 of the prior art, is configured to dampen or absorb theharsh shocks or vibrations coming off the rear end 408 of the front leafspring 394 and the front end 414 of the rear leaf spring 396 proximateto the center frame hangar 372, thereby allowing for a “softer” ride.

When the front leaf spring 394 moves upward, the equalizer 100 rotatesupwardly and to the left relative to the center hangar 372 about pointJ, as illustrated in FIG. 37, such that the rear leaf spring 396 movesdownward, thus equalizing the weight on both the front and rear axles418, 420. Further, when the front leaf spring 394 moves upward, thefirst equalizer arm assembly 366 rotates or pivots upwardly between thefirst and second base plates 104 a, 104 b by the second fastening andsecuring members 122 b, 124 b about a point R. As the first equalizerarm assembly 366 rotates or pivots upwardly, the first lower shock plate110 a of the first equalizer arm assembly 366 is forced against aportion of the outer surface 117 a of the first shock absorber 116 a,thus forcing another portion of the outer surface 117 a against thefirst upper shock plate 112 a. Under this force, the first shockabsorber 116 a deforms between the first lower and upper shock plates110 a, 112 a, such that the first ends 274 a, 282 a of the first lowerand upper shock plates 110 a, 112 a move toward one another and, suchthat the second ends 276 a, 284 a of the first lower and upper shockplates 110 a, 112 a move toward one another. Upon deformation, the firstshock absorber 116 a absorbs or dampens the harsh shocks or vibrationscoming off the rear end 408 of the front leaf spring 394, which wouldotherwise be transferred through the equalizer to the center framehangar 372 and, thus, to the frame 374 of the trailer. Therefore, a“softer” ride is achieved by the suspension system 102 including theequalizer 100 of the present invention.

Likewise, when the rear leaf spring 396 moves upward, the equalizer 100rotates upwardly and to the right relative to the center hangar 372about point J, as illustrated in FIG. 38, such that the front leafspring 394 moves downward, thus equalizing the weight on both the frontand rear axles 418, 420. Further, when the rear leaf spring 396 movesupward, the second equalizer arm assembly 368 rotates or pivots upwardlybetween the first and second base plates 104 a, 104 b by the thirdfastening and securing members 122 c, 124 c about a point S. As thesecond equalizer arm assembly 368 rotates or pivots upwardly, the secondlower shock plate 110 b of the second equalizer arm assembly 368 isforced against a portion of the outer surface 117 b of the second shockabsorber 116 b, thus forcing another portion of the outer surface 117 bagainst the second upper shock plate 112 b. Under this force, the secondshock absorber 116 b deforms between the second lower and upper shockplates 110 b, 112 b, such that the first ends 274 b, 282 b of the secondlower and upper shock plates 110 b, 112 b move toward one another and,such that the second ends 276 b, 284 b of the second lower and uppershock plates 110 b, 112 b move toward one another. Upon deformation, thesecond shock absorber 116 b absorbs or dampens the harsh shocks orvibrations coming off the front end 414 of the rear leaf spring 396,which would otherwise be transferred through the equalizer to the centerframe hangar 372 and, thus, to the frame 374 of the trailer. Therefore,a “softer” ride is achieved by the suspension system 102 including theequalizer 100 of the present invention.

Attention is directed to the second embodiment of an equalizer 500 shownin FIGS. 39-76. The equalizer 500 is provided for use in a suspensionsystem 502, as illustrated in FIG. 39, to equalize the weight on boththe front and rear axles 504, 506 as the tires pass over uneven terrain(as does the equalizer 22 of the prior art suspension system 20), aswell as to dampen or absorb the harsh shocks or vibrations coming off arear end 508 of a front leaf spring 510 on which the front axle 504 ispositioned and a front end 512 of a rear leaf spring 514 on which therear axle 506 is positioned, proximate to the center frame hangar 516,thus allowing for a “softer” ride. As best illustrated in FIGS. 39-44,the equalizer 500 includes first and second base plates 520 a, 520 b,first and second secondary base plates 522 a, 522 b, first and secondequalizer arm castings 524 a, 524 b, an upper shock plate 526, areinforcement plate 528, a shock absorber 530, an upper pivot tube 532,first, second, third, fourth and fifth bushings 534 a, 534 b, 534 c, 534d, 534 e, first and second plug members 536 a, 536 b, and a plasticspacer 538. It should be noted that the configuration of each of thesemembers as shown and described is a preferred configuration of same suchthat the members could be configured in any other suitable manner.

The first base plate 520 a is preferably identical in shape andconfiguration to the second base plate 520 b and, as such, only thefirst base plate 520 a is described with the understanding that thedescription of the second base plate 520 b would be identical. Theelements of the first base plate 520 a will have reference numeralsending in “a”. As such, it is to be understood that the elements of thesecond base plate 520 b will have like reference numerals ending in “b”.

FIGS. 45 and 46 illustrate the first base plate 520 a, which ispreferably formed of a forged, cast or fabricated metal. The first baseplate 520 a has a first planar surface 540 a, a second planar surface542 a, and an edge 544 a which defines a perimeter of the first baseplate 520 a. The first base plate 520 a generally has first, second,third and fourth portions 546 a, 548 a, 550 a, 552 a.

The first portion 546 a of the first base plate 520 a is generallytriangular in configuration such that the edge 544 a extends angularlydownwardly and outwardly from a top 554 a of the first base plate 520 a.The edge 544 a at the top 554 a of the first portion 546 a is generallyrounded.

The second portion 548 a of the first base plate 520 a is generallyrectangular in configuration such that the edge 544 a extends downwardlyfrom the first portion 546 a to the third portion 550 a. The edge 544 aat the connection of the first and second portions 546 a, 548 a isgenerally rounded.

The third portion 550 a of the first base plate 520 a is generallytrapezoidal in configuration such that the edge 544 a extends angularlydownwardly and outwardly from the second portion 548 a to the fourthportion 552 a. The edge 544 a at the connection of the second and thirdportions 548 a, 550 a is generally rounded.

The fourth portion 552 a of the first base plate 520 a is generallytrapezoidal in configuration such that the edge 544 a extends angularlydownwardly and inwardly from the third portion 550 a to a flat bottom556 a of the first base plate 520 a. The edge 544 a at the connection ofthe third and fourth portions 550 a, 552 a is generally rounded and theedge 544 a at the connection of the fourth portion 552 a to the flatbottom 556 a is generally rounded.

A center reference line Y is provided in FIG. 45. The first portion 546a of the first base plate 520 a has an aperture 558 a extendingtherethrough proximate to the top 554 a of the first base plate 520 aThe aperture 558 a is generally bisected by the center reference line Y.The second portion 548 a of the first base plate 520 a has an aperture560 a extending therethrough which is generally bisected by the centerreference line Y. The fourth portion 552 a of the first base plate 520 ahas two apertures 562 a, 564 a extending therethrough which are planarto one another. Aperture 562 a is provided a predetermined distance tothe left from the center reference line Y, and aperture 564 a isprovided a predetermined distance to the right from the center referenceline Y. Each of the apertures 558 a, 560 a, 562 a, 564 a are preferablycircular/cylindrical. Apertures 558 a, 560 a preferably have identicaldiameters and apertures 562 a, 564 a preferably have identicaldiameters, with the diameters of the apertures 558 a, 560 a preferablybeing larger than the diameters of the apertures 562 a, 564 a.

The first secondary base plate 522 a is preferably identical in shapeand configuration to the second secondary base plate 522 b and, as such,only the first secondary base plate 522 a is described with theunderstanding that the description of the second secondary base plate522 b would be identical. The elements of the first secondary base plate522 a will have reference numerals ending in “a”. As such, it is to beunderstood that the elements of the second secondary base plate 522 bwill have like reference numerals ending in “b”.

FIGS. 47-49 illustrate the first secondary base plate 522 a, which ispreferably formed of a forged, cast or fabricated metal. The firstsecondary base plate 522 a has a first planar surface 566 a, a secondplanar surface 568 a, and an edge 570 a which defines a perimeter of thefirst secondary base plate 522 a. The first secondary base plate 522 agenerally has first and second portions 572 a, 574 a.

The first portion 572 a of the first secondary base plate 522 a isgenerally triangular in configuration such that the edge 570 a extendsangularly downwardly and outwardly from a top 576 a of the firstsecondary base plate 522 a. The edge 570 a at the top 576 a of the firstportion 572 a is generally rounded.

The second portion 574 a of the first secondary base plate 522 a isgenerally trapezoidal in configuration such that the edge 570 a extendsangularly downwardly and inwardly from the first portion 572 a to a flatbottom 578 a of the first secondary base plate 522 a. The edge 570 a atthe connection of the first and second portions 572 a, 574 a isgenerally rounded and the edge 570 a at the connection of the secondportion 574 a to the flat bottom 578 a is generally rounded.

A center reference line Y is provided in FIG. 48. The first portion 572a of the first secondary base plate 522 a has an aperture 580 aextending therethrough proximate to the top 576 a of the first secondarybase plate 522 a. The aperture 580 a is generally bisected by the centerreference line Y. The second portion 574 a of the first secondary baseplate 522 a has two apertures 582 a, 584 a extending therethroughproximate to the flat bottom 578 a of the first secondary base plate 522a which are planar to one another. Aperture 582 a is provided apredetermined distance to the left from the center reference line Y, andaperture 584 a is provided a predetermined distance to the right fromthe center reference line Y. Each of the apertures 580 a, 582 a, 584 aare preferably circular/cylindrical. Each of the apertures 580 a, 582 a,584 a preferably have identical diameters, which are identical to thediameters of the apertures 562 a, 564 a of the first base plate 520 a.

The first equalizer arm casting 524 a is preferably identical in shapeand configuration to the second equalizer arm casting 524 b and, assuch, only the first equalizer arm casting 524 a is described with theunderstanding that the description of the second equalizer arm casting524 b would be identical. The elements of the first equalizer armcasting 524 a will have reference numerals ending in “a”. As such, it isto be understood that the elements of the second equalizer arm casting524 b will have like reference numerals ending in “b”.

FIGS. 50-53 illustrate the first equalizer arm casting 524 a, which ispreferably formed of a forged, cast or fabricated metal. The firstequalizer arm casting 524 a has an equalizer arm 586 a, an outer pivottube 588 a, an inner pivot tube 590 a, and a lower shock plate 592 a,which are all preferably integrally formed.

The equalizer arm 586 a is an elongated member having a first planarsurface 594 a, a second planar surface 596 a, and an edge 598 a whichdefines a perimeter of the equalizer arm 586 a. As viewed in FIG. 51,the edge 598 a has a flat bottom 600 a, an outer side 602 a, a top 604a, and an inner side 606 a, all of which are defined by the edge 598 a.The outer side 602 a curves upwardly and outwardly from the flat bottom600 a and then curves upwardly and inwardly to the top 604 a. The innerside 606 a has a first portion 607 a which extends angularly upwardlyand outwardly from the flat bottom 600 a and then a second portion 609 awhich extends angularly upwardly and inwardly to the top 604 a. From theouter side 602 a, the top 604 a has, in series, an outer concave portion608 a, an outer convex portion 610 a, a middle concave portion 612 a, aninner convex portion 614 a, and an inner concave portion 616 a whichextends to the inner side 606 a of the edge 598 a.

The outer pivot tube 588 a is a cylindrical member having an aperture618 a extending entirely therethrough such that inner and outer surfaces620 a, 622 a of the outer pivot tube 588 a are defined. The outer pivottube 588 a extends from a first end 624 a thereof to a second end 626 athereof. The inner surface 620 a of the outer pivot tube 588 a at eachof the first and second ends 624 a, 626 a is preferably chamfered. Theouter pivot tube 588 a is configured to be positioned on/within andsecured to the outer concave portion 610 a of the equalizer arm 586 a.The diameter of the outer surface 622 a of the outer pivot tube 588 a iscommensurate with that at which the outer concave portion 610 a iscurved. The first end 624 a of the outer pivot tube 588 a extends apredetermined distance beyond the first planar surface 594 a of theequalizer arm 586 a and the second end 626 a of the outer pivot tube 588a likewise extends the same predetermined distance beyond the secondplanar surface 596 a of the equalizer arm 586 a.

The inner pivot tube 590 a is a cylindrical member having an aperture628 a extending entirely therethrough such that inner and outer surfaces630 a, 632 a of the inner pivot tube 590 a are defined. A diameter ofthe aperture 628 a is preferably identical to the diameter of theaperture 618 a of the outer pivot tube 588 a, which is also preferablylarger than the diameters of the apertures 562 a, 564 a of the firstbase plate 520 a and the apertures 580 a, 582 a, 584 a of the firstsecondary base plate 522 a. The inner pivot tube 590 a extends from afirst end 634 a thereof to a second end 636 a thereof. The inner surface630 a of the inner pivot tube 590 a at each of the first and second ends634 a, 636 a is preferably chamfered. The inner pivot tube 590 a isconfigured to be positioned on/within and secured to the inner concaveportion 616 a of the equalizer arm 586 a. The diameter of the outersurface 632 a of the inner pivot tube 590 a is commensurate with that atwhich the inner concave portion 616 a is curved. The first end 634 a ofthe inner pivot tube 590 a extends a predetermined distance beyond thefirst planar surface 594 a of the equalizer arm 586 a and the second end636 a of the inner pivot tube 590 a likewise extends the samepredetermined distance beyond the second planar surface 596 a of theequalizer arm 586 a. The distance between the first and second ends 634a, 636 a of the inner pivot tube 590 a is preferably less than adistance between the first and second ends 624 a, 626 a of the outerpivot tube 588 a.

The lower shock plate 592 a is a thin plate which has first and secondends 638 a, 640 a, inner and outer ends 642 a, 644 a, and top and bottomsurfaces 646 a, 648 a. The lower shock plate 592 a is curved in aconcave manner from the inner end 642 a thereof to the outer end 644 athereof. The lower shock plate 592 a is configured to have the bottomsurface 648 a thereof be positioned on/within and secured to the middleconcave portion 612 a of the equalizer arm 586 a. The curving of thebottom surface 648 a of the lower shock plate 592 a is generallycommensurate with that at which the middle concave portion 612 a iscurved. The first end 638 a of the lower shock plate 592 a extends apredetermined distance beyond the first planar surface 594 a of theequalizer arm 586 a and the second end 640 a of the lower shock plate592 a likewise extends the same predetermined distance beyond the secondplanar surface 596 a of the equalizer arm 586 a. The distance betweenthe first and second ends 638 a, 640 a of the lower shock plate 592 a ispreferably identical to the distance between the first and second ends634 a, 636 a of the inner pivot tube 590 a. The outer end 644 a of thelower shock plate 592 a is configured to connect to the outer surface622 a of the outer pivot tube 588 a, and to bend around the outer convexportion 610 a of the top 604 a of the equalizer arm 586 a. The inner end642 a of the lower shock plate 592 a is configured to connect to theouter surface 632 a of the inner pivot tube 590 a, and to bend aroundthe inner convex portion 614 a of the top 604 a of the equalizer arm 586a.

FIGS. 54-56 illustrate the upper shock plate 526, which is preferablyformed of a forged, cast or fabricated metal. The upper shock plate 526is a thin plate which has first and second side ends 650, 652, first andsecond outer ends 654, 656, and top and bottom surfaces 658, 660. Theupper shock plate 526 has, from the first outer end 654 to the secondouter end 656, in series, a first outer straight portion 662, a firstcurved portion 664, a middle straight portion 666, a second curvedportion 668, and a second outer straight portion 670. The first andsecond curved portions 664, 668 are curved downwardly and outwardly fromthe ends of the middle straight portion 666. The first outer straightportion 662 extends downwardly and outwardly from the first curvedportion 664, such that it is at an angle relative to the middle straightportion 666. The second outer straight portion 670 extends downwardlyand outwardly from the second curved portion 668, such that it is at anangle relative to the middle straight portion 666, and such that it isgenerally perpendicular to the first outer straight portion 662.

FIGS. 57 and 58 illustrate the reinforcement plate 528, which ispreferably formed of a forged, cast or fabricated metal. Thereinforcement plate 528 has a first planar surface 672, a second planarsurface 674, and an edge 676 which defines a perimeter of thereinforcement plate 528.

The reinforcement plate 528 is generally trapezoidal in configurationsuch that the edge 676 includes a flat bottom 678, first and secondsides 680, 682, and a top 684. The first and second sides 680, 682 areangled upwardly and inwardly from the ends of the flat bottom 678 to thetop 684. The edge 676 at the connection of the first and second sides680, 682 to the flat bottom 678 is generally rounded. The edge 676 atthe connection of the first and second sides 680, 682 to the top 684 isalso generally rounded. The top 684 has a concave portion 686 formedtherein which extends from proximate the connection of the first side680 to the top 684 to proximate the connection of the second side 682 tothe top 684.

FIGS. 59-61 illustrate the shock absorber 530, which is preferablyformed of an elastomeric material, such as rubber, and preferablyTORSILASTIC® rubber. The shock absorber 530 has a first planar surface686, a second planar surface 688, and an edge 690 which defines aperimeter of the shock absorber 530. The shock absorber 530 generallyhas first, second, third and fourth portions 692, 694, 696, 698.

The first portion 692 of the shock absorber 530 is generally trapezoidalin configuration such that the edge 690 extends angularly downwardly andoutwardly from a flat top 700 of the shock absorber 530. The edge 690 atthe connection to the flat top 700 is generally rounded.

The second portion 694 of the shock absorber 530 is generallyrectangular in configuration and is positioned below the first portion692 of the shock absorber 530, and extends to a flat bottom 702 of theshock absorber 530, although the edge 690 is rounded or arced from thefirst portion 692 to the flat bottom 702.

The third and fourth portions 696, 698 of the shock absorber 530 aregenerally configured as segments of a circle. The third portion 696 ispositioned below the flat bottom 702 at the left side of the shockabsorber 530 and extends inwardly, and the fourth portion 698 ispositioned below the flat bottom 702 at the right side of the shockabsorber 530 and extends inwardly, such that the flat bottom 702 of theshock absorber 530 is visibly provided between the third and fourthportions 696, 698. The edge 690 on the third and fourth portions 696,698 is generally continuously curved from the curve of the edge 690provided on the second portion 694.

The shock absorber 530 is thus generally formed in the shape of anupside-down heart.

A center reference line Y is provided in FIG. 60. The first portion 692of the shock absorber 530 has an aperture 704 extending therethroughwhich is generally bisected by the center reference line Y. The secondportion 694 of the shock absorber 530 has two apertures 706, 708extending therethrough which are planar to one another. Aperture 706 isprovided at a predetermined distance to the left from the centerreference line Y, and is preferably centered over the third portion 696of the shock absorber 530. Aperture 708 is provided at a predetermineddistance to the right from the center reference line Y, and ispreferably centered over the fourth portion 698 of the shock absorber530. Each of the apertures 704, 706, 708 are preferablycircular/cylindrical. Apertures 706, 708 preferably have identicaldiameters, with a diameter of the aperture 704 being larger than thediameters of the apertures 706, 708. The diameter of the aperture 704 ispreferably larger than the diameter of the aperture 560 a providedthrough the second portion 548 a of the first base plate 520 a.

FIGS. 71-73 illustrate the upper pivot tube 532, which is preferablyformed of a forged, cast or fabricated metal. The upper pivot tube 532is a cylindrical member having an aperture 710 extending entirelytherethrough such that inner and outer surfaces 712, 714 of the upperpivot tube 532 are defined. The upper pivot tube 532 extends from afirst end 716 thereof to a second end 718 thereof. The inner surface 712of the upper pivot tube 532 at each of the first and second ends 716,718 is preferably chamfered.

Each of the bushings 534 a, 534 b, 534 c, 534 d, 534 e are generallyidentical to one another in shape and configuration (although the first,second and third bushings 534 a, 534 b, 534 c have a longer length thando the fourth and fifth bushings 534 d, 534 e) and, as such, only thefirst bushing 534 a is described with the understanding that thedescription of the second, third, fourth and fifth bushings 534 b, 534c, 534 d, 534 e would be identical. The elements of the first bushing534 a will have reference numerals ending in “a”. As such, it is to beunderstood that the elements of the second, third, fourth and fifthbushings 534 b, 534 c, 534 d, 534 e will have like reference numeralsending in “b”, “c”, “d” and “e”, respectively.

FIGS. 65-67 illustrate the first bushing 534 a, which is preferablyformed of metal, such as brass. The first bushing 534 a is a cylindricalmember having an aperture 720 a extending entirely therethrough suchthat inner and outer surface 722 a, 724 a of the first bushing 534 a aredefined. The first bushing 534 a extends from a first end 726 a thereofto a second end 728 a thereof. The inner surface 722 a of the firstbushing 534 a at each of the first and second ends 726 a, 728 a ispreferably chamfered.

Each of the plug members 536 a, 536 b are generally identical to oneanother in shape and configuration and, as such, only the first plugmember 536 a is described with the understanding that the description ofthe second plug member 536 b would be identical. The elements of thefirst plug member 536 a will have reference numerals ending in “a”. Assuch, it is to be understood that the elements of the second plug member536 b will have like reference numerals ending in “b”.

FIGS. 68-70 illustrate the first plug member 536 a, which is preferablyformed of an elastomeric material, such as rubber, and preferablyTORSILASTIC® rubber. The first plug member 536 a is a cylindrical memberdefining an outer surface 730 a. The first plug member 536 a extendsfrom a first end 732 a thereof to a second end 734 a thereof.

FIGS. 62-64 illustrate the spacer 538, which is preferably formed of aplastic material. The spacer 538 is a cylindrical member having anaperture 736 extending entirely therethrough such that inner and outersurfaces 738, 740 of the spacer 538 are defined. The spacer 538 extendsfrom a first end 742 thereof to a second end 744 thereof. The innersurface 738 of the spacer 538 at each of the first and second ends 742,744 is preferably chamfered.

FIGS. 39-44 and 74 illustrate the construction of the equalizer 500alone and in conjunction with the suspension system 502, as well as thefunction of the equalizer 500 with the suspension system 502. It shouldbe noted that the order of the construction of the equalizer 500 asdescribed is not the only order in which the equalizer 500 may beconstructed.

The fourth and fifth bushings 534 d, 534 e are inserted and securedwithin the apertures 628 a, 628 b of the inner pivot tubes 590 a, 590 bof the first and second equalizer arm castings 524 a, 524 b,respectively, such that the outer surfaces 724 d, 724 e of the fourthand fifth bushings 534 d, 534 e are positioned against the innersurfaces 630 a, 630 b of the inner pivot tubes 590 a, 590 b. The fourthand fifth bushings 534 d, 534 e are further secured within the apertures628 a, 628 b of the inner pivot tubes 590 a, 590 b, respectively, suchthat the first ends 726 d, 726 e of the fourth and fifth bushings 534 d,534 e are provided proximate to or flush with the first ends 634 a, 634b of the inner pivot tubes 590 a, 590 b, and such that the second ends728 d, 728 e of the fourth and fifth bushings 534 d, 534 e are providedproximate to or flush with the second ends 636 a, 636 b of the innerpivot tubes 590 a, 590 b.

The second and third bushings 534 b, 534 c are inserted and securedwithin the apertures 618 a, 618 b of the outer pivot tubes 588 a, 588 bof the first and second equalizer arm castings 524 a, 524 b,respectively, such that the outer surfaces 724 b, 724 c of the secondand third bushings 534 b, 534 c are positioned against the innersurfaces 620 a, 620 b of the outer pivot tubes 588 a, 588 b. The secondand third bushings 534 b, 534 c are further secured within the apertures618 a, 618 b of the outer pivot tubes 588 a, 588 b such that the firstends 726 b, 726 c of the second and third bushings 534 b, 534 c areprovided proximate to or flush with the first ends 624 a, 624 b of theouter pivot tubes 588 a, 588 b, and such that the second ends 728 b, 728c of the second and third bushings 534 b, 534 c are provided proximateto or flush with the second end 626 a, 626 b of the outer pivot tubes588 a, 588 b.

The first bushing 534 a is inserted into and secured within the aperture710 of the upper pivot tube 532 such that the outer surface 724 a of thefirst bushing 534 a is positioned against the inner surface 712 of theupper pivot tube 532. The first bushing 534 a is further secured withinthe aperture 710 of the upper pivot tube 532 such that the first end 726a of the first bushing 534 a is provided proximate to or flush with thefirst end 716 of the upper pivot tube 532, and such that the second end728 a of the first bushing 534 a is provided proximate to or flush withthe second end 718 of the upper pivot tube 532.

The first plug member 536 a is inserted into the aperture 706 of theshock absorber 530 in order to fully or partially plug up the aperture706, as desired, of the shock absorber 530 and, as such, may either befixedly secured within the aperture 706 or loose within the aperture706. Likewise, the second plug member 536 b is inserted into theaperture 708 of the shock absorber 530 in order to fully or partiallyplug up the aperture 708, as desired, of the shock absorber 530 and, assuch, may either be fixedly secured within the aperture 708 or loosewithin the aperture 708.

The spacer 538 is inserted into the aperture 704 of the shock absorber530 and may either be fixedly secured within the aperture 704 or loosewithin the aperture 704.

The upper pivot tube 532 is positioned within the aperture 558 b of thesecond base plate 520 b such that the second end 718 of the upper pivottube 532 is substantially flush with the second planar surface 542 b ofthe second base plate 520 b. The outer surface 714 of the upper pivottube 532 is fixedly secured to the second base plate 520 b, preferablyby welding.

The second side end 652 of the upper shock plate 526 is positioned andsecured against, preferably by welding, the first planar surface 540 bof the second base plate 520 b. The first and second outer ends 654, 656are preferably flush with the edge 544 b of the second base plate 520 bat the second portion 548 b thereof. The middle straight portion 666 ofthe upper shock plate 526 is preferably, thus, positioned between theapertures 558 b, 560 b extending through the second base plate 520 b.

The flat bottom 678 of the edge 676 of the reinforcement plate 528 ispositioned to rest on the top surface 658 of the middle straight portion666 of the upper shock plate 526 such that the first planar surface 672of the reinforcement plate 528 is preferably flush with the first sideend 650 of the upper shock plate 526. The outer surface 714 of the upperpivot tube 532, proximate to the first end 716 thereof, rests within theconcave portion 686 of the top 684 of the edge 676 of the reinforcementplate 528, such that the first end 716 of the upper pivot tube 532 ispreferably flush with the first planar surface 672 of the reinforcementplate 528.

The first equalizer arm casting 524 a is aligned with the second baseplate 520 b such that the second planar surface 596 a of the equalizerarm 586 a faces the first planar surface 540 b of the second base plate520 b and such that the aperture 720 d of the fourth bushing 534 d, andthus the aperture 628 a of the inner pivot tube 590 a, are incommunication with the aperture 562 b of the second base plate 520 b.

The second equalizer arm casting 524 b is aligned in an opposite mannerwith the with the second base plate 520 b such that the first planarsurface 594 b of the equalizer arm 586 b faces the first planar surface540 b of the second base plate 520 b and such that the aperture 720 e ofthe fifth bushing 534 e, and thus the aperture 628 b of the inner pivottube 590 b, are in communication with the aperture 564 b of the secondbase plate 520 b. As such, the first portions 607 a, 607 b of theequalizer arms 586 a, 586 b are generally planar with and positionednext to one another, and the second portions 609 a, 609 b of theequalizer arms 586 a, 586 b generally face one another.

The second planar surface 688 of the shock absorber 530 is positioned toface the first planar surface 540 b of the second base plate 520 b. Theflat bottom 702 of the shock absorber 530 is positioned above the outersurfaces 632 a, 632 b of the inner pivot tubes 590 a, 590 b of the firstand second equalizer arm castings 524 a, 524 b.

The edge 690 about the third portion 696 of the shock absorber 530 ispositioned to rest on the top surface 646 a of the lower shock plate 592a of the first equalizer arm casting 524 a, with the curve of the edge690 about the third portion 696 of the shock absorber 530 generallymatching the curve of the top surface 646 a of the lower shock plate 592a.

The edge 690 about the fourth portion 698 of the shock absorber 530 ispositioned to rest on the top surface 646 b of the lower shock plate 592b of the second equalizer arm casting 524 b, with the curve of the edge690 about the fourth portion 698 of the shock absorber 530 generallymatching the curve of the top surface 646 b of the lower shock plate 592b.

The bottom surface 660 of the upper shock plate 526 is configured toface and/or abut against the edge 690 of the first portion 692 of theshock absorber 530, with the middle straight portion 666 of the uppershock plate 526 facing and/or abutting against the flat top 700 of theshock absorber 530.

In this position, the aperture 736 through the spacer 538, and thus theaperture 704 through the shock absorber 530, are in communication withthe aperture 560 b through the second base plate 520 b.

The first base plate 520 a is positioned such that the second planarsurface 542 a thereof faces the first planar surface 594 a of the firstequalizer arm 586 a and the second planar surface 596 b of the secondequalizer arm 586 b, and such that the second planar surface 542 athereof faces and/or abuts against the first planar surface 672 of thereinforcement plate 528, the first side end 650 of the upper shock plate526, the first planar surface 686 of the shock absorber 530, the firstend 638 a of the lower shock plate 592 a, the second end 640 b of thelower shock plate 592 b, the first end 634 a of the inner pivot tube 590a, and the second end 636 b of the inner pivot tube 590 b.

The first end 716 of the upper pivot tube 532 does not extend into theaperture 558 a of the first base plate 520 a, but the aperture 720 a ofthe first bushing 534 a is in communication with the aperture 558 a ofthe first base plate 520 a. The aperture 736 through the spacer 538, andthus the aperture 704 through the shock absorber 530, are incommunication with the aperture 560 a through the first base plate 520a. The aperture 720 d of the bushing 534 d provided in the aperture 628a of the inner pivot tube 590 a is in communication with the aperture562 a of the first base plate 520 a, and the aperture 720 e of thebushing 534 e provided in the aperture 630 b of the inner pivot tube 590b is in communication with the aperture 564 a of the first base plate520 a.

The first planar surface 568 b of the second secondary base plate 522 bfaces and/or abuts against the second planar surface 542 b of the secondbase plate 520 b such that the aperture 580 b is in alignment with theaperture 560 b, such that the aperture 582 b is in alignment with theaperture 562 b, and such that the aperture 584 b is in alignment withthe aperture 564 b.

The second planar surface 566 a of the first secondary base plate 522 afaces and/or abuts against the first planar surface 540 a of the firstbase plate 520 a such that the aperture 580 a is in alignment with theaperture 560 a, such that the aperture 582 a is in alignment with theaperture 562 a, and such that the aperture 584 a is in alignment withthe aperture 564 a.

A first fastening member 750 a, illustrated in FIG. 75, such as a bolt,having an enlarged head portion 752 a and an elongated shank portion 754a extending therefrom is inserted through the aperture 580 a of thefirst secondary base plate 522 a, through the aperture 560 a of thefirst base plate 520 a, through the aperture 736 of the spacer 538,through the aperture 560 b of the second base plate 520 b, and throughthe aperture 580 b of the second secondary base plate 522 b such thatthe enlarged head portion 752 a is positioned against the first planarsurface 566 a of the first secondary base plate 522 a. A first securingmember 756 a, illustrated in FIG. 76, such as a nut, having an aperture758 a provided therethrough, is positioned with the elongated shankportion 754 a extending through the aperture 758 a and the firstsecuring member 756 a is positioned against the second planar surface568 b of the second secondary base plate 522 b.

A second fastening member 750 b, such as a bolt, having an enlarged headportion 752 b and an elongated shank portion 754 b extending therefromis inserted through the aperture 582 a of the first secondary base plate522 a, through the aperture 562 a of the first base plate 520 a, throughthe aperture 720 d of the fourth bushing 534 d, through the aperture 562b of the second base plate 520 b, and through the aperture 582 b of thesecond secondary base plate 522 b such that the enlarged head portion752 b is positioned against the first planar surface 566 a of the firstsecondary base plate 522 a. A first securing member 756 b, such as anut, having an aperture 758 b provided therethrough, is positioned withthe elongated shank portion 754 b extending through the aperture 758 band the first securing member 756 b is positioned against the secondplanar surface 568 b of the second secondary base plate 522 b.

A third fastening member 750 c, such as a bolt, having an enlarged headportion 752 c and an elongated shank portion 754 c extending therefromis inserted through the aperture 584 a of the first secondary base plate522 a, through the aperture 564 a of the first base plate 520 a, throughthe aperture 720 e of the fifth bushing 534 e, through the aperture 564b of the second base plate 520 b, and through the aperture 584 b of thesecond secondary base plate 522 b such that the enlarged head portion752 c is positioned against the first planar surface 566 a of the firstsecondary base plate 522 a. A first securing member 756 c, such as anut, having an aperture 758 c provided therethrough, is positioned withthe elongated shank portion 754 c extending through the aperture 758 cand the first securing member 756 c is positioned against the secondplanar surface 568 b of the second secondary base plate 522 b.

The equalizer 500 of the invention is thus constructed as illustrated inFIGS. 39-43. Different fastening members 750 a, 750 b, 750 c can beutilized as desired to provide for greasable or non-greasable pivots.

As illustrated in FIG. 39, the equalizer 500 is secured to the centerframe hangar 516 which depends from a frame 760 of a trailer (notshown). The center frame hangar 516 is generally U-shaped such that ithas a base portion and first and second portions 764, 766 which extenddownwardly from opposite ends of the base portion. The base portion isfixedly secured to the frame 760 of the trailer by known means, such aswelding. The first extending portion 764 has an aperture (not shown)extending therethrough proximate to a free end thereof. The secondextending portion 766 has an aperture (not shown) extending therethroughproximate to a free end thereof. The aperture of the extending portions764, 766 are in alignment with one another and the free ends arepreferably planar.

As illustrated in FIG. 39, the first and second base plates 520 a, 520 bare positioned between the first and second extending portions 764, 766of the center frame hangar 516 such that the first planar surface 540 aof the first base plate 520 a faces the first extending portion 764, andsuch that the second planar surface 542 b of the second base plate 520 bfaces the second extending portion 766. The aperture 558 a of the firstbase plate 520 a is in alignment with the aperture of the firstextending portion 764 of the center frame hangar 516. Likewise, theaperture 558 b of the second base plate 520 b is in alignment with theaperture of the second extending portion 766 of the center frame hangar516. A fastening member, which may be identical to or different from thefastening members 750 a, 750 b, 750 c can be inserted through theapertures 768, 558 a, 720 a, 558 b, 772. A securing member, which may beidentical to or different from the securing members 756 a, 756 b, 756 ccan then be secured to the fastening member such that the equalizer 500is rotatably secured or pivotally mounted between the first and secondextending portions 764, 766 of the center frame hangar 516.

As illustrated in FIG. 39, the suspension system 502 includes theequalizer 500, a front leaf spring 510, a rear leaf spring 514, a frontshackle or link 780, and a rear shackle or link 782. As discussed, theequalizer 500 is rotatably secured or pivotally mounted to the centerframe hangar 516 of the frame 760 of the trailer, illustrated at a pointJ. A first end of the front shackle 780 is rotatably secured orpivotally mounted to the outer pivot tube 588 a of the first equalizerarm casting 524 a, at a point K, preferably by a fastening member and asecuring member. The fastening member extends through apertures of thefront shackle 780 and the aperture 720 b of the second bushing 534 b. Afirst end of the rear shackle 782 is rotatably secured or pivotallymounted to the outer pivot tube 588 b of the second equalizer armcasting 524 b, at a point L, preferably by a fastening member and asecuring member. The fastening member extends through the apertures ofthe rear shackle 782 and the aperture 720 c of the third busing 534 c.The fastening members may be identical to or different from thefastening members 750 a, 750 b, 750 c. The securing members may beidentical or different from the securing members 756 a, 756 b, 756 c.

A second end of the front shackle 780 is rotatably secured or pivotallymounted to the rear end 508 of the front leaf spring 510 at a point M. Afront end 790 of the front leaf spring 510 is attached to a front framehangar 792 at a point N, or can be directly attached to the frame 760itself, depending on the configuration of the frame 760.

A second end of the rear shackle 782 is rotatably secured or pivotallymounted to the front end 512 of the rear leaf spring 514 at a point P. Arear end of the rear leaf spring 514 is attached to a rear frame hangar798 at a point Q, or can be directly attached to the frame 760 itself,depending on the configuration of the frame 760.

The front axle 504 of the trailer is positioned on the forward leafspring 510 generally equidistantly between point M and point N. The rearaxle 506 is positioned on the rear leaf spring 514 generallyequidistantly between point P and point Q.

It is to be understood that while only a single suspension system 502 isillustrated and described, it is typical to have one suspension system502 provided on both a left and a right side of a trailer. If more thantwo axles are provided on the trailer, it is to be understood that twoor more suspension systems 502 can be provided on both a left and aright side of the trailer.

Like the prior art suspension system 20 including the equalizer 20illustrated in FIG. 1, to the extent possible, road shock and vibrationsfrom tires (not shown) of the trailer, utilizing the suspension system502 including the equalizer 500 of the present invention, aretransferred to the front and rear axles 504, 506, and are absorbed bythe front and rear leaf springs 510, 514, respectively. Points J, N andQ are the contact points through which the road shock is passed to theframe 760. The equalizer 500 is included in the suspension system 502 inorder to equalize the weight on both the front and rear axles 504, 506as the tires pass over uneven terrain. For example, an upward motion ofthe front leaf spring 504 results in a downward motion of the rear leafspring 506.

The equalizer 500, like the equalizer 100, and unlike the equalizer 22of the prior art, is configured to dampen or absorb the harsh shocks orvibrations coming off the rear end 508 of the front leaf spring 510 andthe front end 512 of the rear leaf spring 514 proximate to the centerframe hangar 516, thereby allowing for a “softer” ride.

When the front leaf spring 510 moves upward, the equalizer 500 rotatesupwardly and to the left relative to the center hangar 516 about point Jsuch that the rear leaf spring 514 moves downward, thus equalizing theweight on both the front and rear axles 504, 506. Further, when thefront leaf spring 510 moves upward, the first equalizer arm casting 524a rotates or pivots upwardly between the first and second base plates520 a, 502 b by the second fastening and securing members 750 b, 756 babout a point R. As the first equalizer arm casting 524 a rotates orpivots upwardly, the lower shock plate 592 a of the first equalizer armcasting 524 a is forced against the third portion 696 of the shockabsorber 530, thus forcing the first portion 692 of the shock absorber530 against the upper shock plate 526. Under this force, the shockabsorber 530 deforms between the upper and lower shock plates 526, 592a. Upon deformation, the shock absorber 530 absorbs or dampens the harshshocks or vibrations coming off the rear end 508 of the front leafspring 510, which would otherwise be transferred through the equalizerto the center frame hangar 516 and, thus, to the frame 760 of thetrailer. Therefore, a “softer” ride is achieved by the suspension system502 including the equalizer 500.

When the rear leaf spring 514 moves upward, the equalizer 500 rotatesupwardly and to the right relative to the center hangar 516 about pointJ such that the front leaf spring 510 moves downward, thus equalizingthe weight on both the front and rear axles 504, 506. Further, when therear leaf spring 514 moves upward, the second equalizer arm casting 524b rotates or pivots upwardly between the first and second base plates520 a, 502 b by the third fastening and securing members 750 c, 756 cabout a point S. As the second equalizer arm casting 524 b rotates orpivots upwardly, the lower shock plate 592 b of the second equalizer armcasting 524 b is forced against the fourth portion 698 of the shockabsorber 530, thus forcing the first portion 692 of the shock absorber530 against the upper shock plate 526. Under this force, the shockabsorber 530 deforms between the upper and lower shock plates 526, 592b. Upon deformation, the shock absorber 530 absorbs or dampens the harshshocks or vibrations coming off the front end 512 of the rear leafspring 514, which would otherwise be transferred through the equalizerto the center frame hangar 516 and, thus, to the frame 760 of thetrailer. Therefore, a “softer” ride is achieved by the suspension system502 including the equalizer 500.

The equalizer 500 is preferably used for tandem axle configurationshaving a load range of approximately 12,000 pounds to 14,000 pounds. Fortandem axle configurations having a load range of approximately 10,000pounds to 12,000 pounds, the equalizer 500 may be altered by removingthe plug members 536 a, 536 b from within the apertures 706, 708 of theshock absorber 530. For tandem axle configurations having a load rangeof approximately 8,000 pounds to 10,000 pounds, the equalizer 500 may bealtered by removing the plug members 536 a, 536 b from within theapertures 706, 708 of the shock absorber 530, and by removing the spacer538 from within the aperture 704 of the shock absorber 530. It has beenfound that sizing the shock absorber 530 for the load goes hand in handwith performance. If too little or too much material is used in theshock absorber 530, the ride quality will suffer; the two are linked.Thus, other variations of the shock absorber 830 with, partially with,or without the plug members 836 a, 836 b, can be used as desired foroptimum performance.

For tandem axle configurations having a load range of less thanapproximately 8,000 pounds, use of the equalizer 800, illustrated inFIGS. 77-97, is preferred. The equalizer 800 includes first and secondbase plates 820 a, 820 b, first and second secondary base plates 822 a,822 b, first and second equalizer arm castings 824 a, 824 b, an uppershock plate 826, a shock absorber 830, an upper pivot tube 832, first,second, third, fourth and fifth bushings 834 a, 834 b, 834 c, 834 d, 834e, and first and second plug members 836 a, 836 b. It should be notedthat the configuration of each of these members as shown and describedis a preferred configuration of same such that the members could beconfigured in any other suitable manner.

The upper shock plate 826 is generally identical to the upper shockplate 826 of the second embodiment of the equalizer 500 and, therefore,the upper shock plate 826 will not be specifically described and/orillustrated with the understanding that like elements in the upper shockplates 526, 826 are denoted with like reference numerals.

The upper pivot tube 832 is generally identical to the upper pivot tube532 of the second embodiment of the equalizer 500 and, therefore, theupper pivot tube 832 will not be specifically described and/orillustrated with the understanding that like elements in the upper pivottubes 532, 832 are denoted with like reference numerals.

The bushings 834 a, 834 b, 834 c, 834 d, 834 e are generally identicalto the bushings 534 a, 534 b, 534 c, 534 d, 534 e of the secondembodiment of the equalizer 500 and, therefore, the bushings 834 a, 834b, 834 c, 834 d, 834 e will not be specifically described and/orillustrated with the understanding that like elements in the bushings534 a, 534 b, 534 c, 534 d, 534 e; 834 a, 834 b, 834 c, 834 d, 834 e aredenoted with like reference numerals.

The plug members 836 a, 836 b are generally identical to the plugmembers 536 a, 536 b of the second embodiment of the equalizer 500 and,therefore, the plug members 836 a, 836 b will not be specificallydescribed and/or illustrated with the understanding that like elementsin the bushings 536 a, 536 b; 836 a, 836 b are denoted with likereference numerals.

The first base plate 820 a is preferably identical in shape andconfiguration to the second base plate 820 b and, as such, only thefirst base plate 820 a is described with the understanding that thedescription of the second base plate 820 b would be identical. Theelements of the first base plate 820 a will have reference numeralsending in “a”. As such, it is to be understood that the elements of thesecond base plate 820 b will have like reference numerals ending in “b”.

FIGS. 83 and 84 illustrate the first base plate 820 a, which ispreferably formed of a forged, cast or fabricated metal. The first baseplate 820 a has a first planar surface 840 a, a second planar surface842 a, and an edge 844 a which defines a perimeter of the first baseplate 820 a. The first base plate 820 a generally has first, second,third and fourth portions 846 a, 848 a, 850 a, 852 a.

The first portion 846 a of the first base plate 820 a is generallytriangular in configuration such that the edge 844 a extends angularlydownwardly and outwardly from a top 854 a of the first base plate 820 a.The edge 844 a at the top 854 a of the first portion 846 a is generallyrounded.

The second portion 848 a of the first base plate 820 a is generallyrectangular in configuration such that the edge 844 a extends downwardlyfrom the first portion 846 a to the third portion 850 a. The edge 844 aat the connection of the first and second portions 846 a, 848 a isgenerally rounded.

The third portion 850 a of the first base plate 820 a is generallytrapezoidal in configuration such that the edge 844 a extends angularlydownwardly and outwardly from the second portion 848 a to the fourthportion 852 a. The edge 844 a at the connection of the second and thirdportions 848 a, 850 a is generally rounded.

The fourth portion 852 a of the first base plate 820 a is generallytriangular in configuration such that the edge 544 a extends angularlydownwardly and inwardly from the third portion 850 a to a bottom 856 aof the first base plate 820 a. The edge 844 a at the connection of thethird and fourth portions 850 a, 852 a is generally rounded and the edge844 a at the bottom 856 a of the fourth portion 852 a is generallyrounded.

A center reference line Y is provided in FIG. 83. An aperture 858 aextends through the first base plate 820 a. The aperture 858 a isgenerally bisected by the first and second portions 846 a, 848 a, and bythe center reference line Y. The fourth portion 852 a of the first baseplate 820 a has an aperture 863 a extending therethrough proximate tothe bottom 856 a, which is generally bisected by the center referenceline Y. Each of the apertures 858 a, 863 a are preferablycircular/cylindrical. Aperture 858 a has a diameter which is larger thana diameter of the aperture 863 a.

The first secondary base plate 822 a is preferably identical in shapeand configuration to the second secondary base plate 822 b and, as such,only the first secondary base plate 822 a is described with theunderstanding that the description of the second secondary base plate822 b would be identical. The elements of the first secondary base plate822 a will have reference numerals ending in “a”. As such, it is to beunderstood that the elements of the second secondary base plate 822 bwill have like reference numerals ending in “b”.

FIGS. 93-95 illustrate the first secondary base plate 822 a, which ispreferably formed of a forged, cast or fabricated metal. The firstsecondary base plate 822 a has a first planar surface 866 a, a secondplanar surface 868 a, and an edge 870 a which defines a perimeter of thefirst secondary base plate 822 a. The first secondary base plate 822 ais generally formed in a shape of a circular disc such that the edge 870a is circular/cylindrical.

An aperture 883 a is provided generally through a center of the firstsecondary base plate 822 a. The aperture 883 a is preferablycircular/cylindrical. Aperture 883 preferably has a diameter which isidentical to the diameter of aperture 863 a of the first base plate 820a The second equalizer arm casting 824 b is preferably identical inshape and configuration to the first equalizer arm casting 824 a and, assuch, only the second equalizer arm casting 824 b is described with theunderstanding that the description of the first equalizer arm casting824 a would be identical. The elements of the second equalizer armcasting 824 b will have reference numerals ending in “b”. As such, it isto be understood that the elements of the first equalizer arm casting824 a will have like reference numerals ending in “a”.

FIGS. 85-88 illustrate the second equalizer arm casting 824 b, which ispreferably formed of a forged, cast or fabricated metal. The secondequalizer arm casting 824 b has an equalizer arm 886 b, an outer pivottube 888 b, an inner pivot tube 890 b, and a lower shock plate 892 b,which are all preferably integrally formed.

The equalizer arm 886 b is an elongated member having a first surface894 b, a second surface 896 b, and an edge 898 b which defines aperimeter of the equalizer arm 886 b. As viewed in FIG. 86, the edge 898b has a flat bottom 900 b, an outer side 902 b, a top 904 b, and aninner side 906 b, all of which are defined by the edge 898 b. The outerside 902 b curves upwardly and outwardly from the flat bottom 900 b andthen extends straight upwardly and outwardly to the top 904 b. The innerside 906 b extends straight upwardly and inwardly from the flat bottom900 b to the top 904 b. From the outer side 902 b, the top 904 b has, inseries, an outer concave portion 908 b, a convex portion 910 b, a middleconcave portion 912 b, and an inner concave portion 916 b which extendsto the inner side 906 b of the edge 898 b. A distance from the firstsurface 894 b to the second surface 896 b is larger proximate to theinner side 906 b than it is proximate to the outer side 902 b, such thatthe equalizer arm 886 b has an increased width portion proximate to theinner side 906 b and a decreased width portion proximate to the outerside 902 b. The inner concave portion 916 b is generally provided in theincreased width portion and the outer and middle concave portions 908 b,912 b and the convex portion 910 b are generally provided in thedecreased width portion.

The outer pivot tube 888 b is a cylindrical member having an aperture918 b extending entirely therethrough such that inner and outer surfaces920 b, 922 b of the outer pivot tube 888 b are defined. The outer pivottube 888 b extends from a first end 924 b thereof to a second end 926 bthereof. The inner surface 920 b of the outer pivot tube 888 b at eachof the first and second ends 924 b, 926 b is preferably chamfered. Theouter pivot tube 888 b is configured to be positioned on/within andsecured to the outer concave portion 910 b of the equalizer arm 886 b.The diameter of the outer surface 922 b of the outer pivot tube 888 b iscommensurate with that at which the outer concave portion 910 b iscurved. The first end 924 b of the outer pivot tube 888 b extends apredetermined distance beyond the first surface 894 b of the equalizerarm 886 b and the second end 926 b of the outer pivot tube 888 blikewise extends the same predetermined distance beyond the secondsurface 896 b of the equalizer arm 886 b.

The inner pivot tube 890 b is a cylindrical member having an aperture928 b extending entirely therethrough such that inner and outer surfaces930 b, 932 b of the inner pivot tube 890 b are defined. A diameter ofthe aperture 928 b is preferably identical to the diameter of theaperture 918 b of the outer pivot tube 888 b, which is also preferablylarger than the diameter of the aperture 863 a of the first base plate820 a and the diameter of the aperture 883 a of the first secondary baseplate 822 a. The inner pivot tube 890 b extends from a first end 934 bthereof to a second end 936 b thereof. The inner surface 930 b of theinner pivot tube 890 b at each of the first and second ends 934 b, 936 bis preferably chamfered. The inner pivot tube 890 b is configured to bepositioned on/within and secured to the inner concave portion 916 b ofthe equalizer arm 886 b. The diameter of the outer surface 932 b of theinner pivot tube 890 b is commensurate with that at which the innerconcave portion 916 b is curved. The first end 934 b of the inner pivottube 890 b extends generally to a middle of the first and secondsurfaces 894 b, 896 b of the equalizer arm 886 b. The second end 936 bof the inner pivot tube 890 extends beyond the first surface 894 b ofthe equalizer arm 886 b.

The lower shock plate 892 b has first and second ends 938 b, 940 b,inner and outer ends 942 b, 944 b, and top and bottom surfaces 946 b,948 b. The lower shock plate 892 b is curved in a concave manner fromthe inner end 942 b thereof to proximate the outer end 944 b thereof,and then is curved in a convex manner to the outer end 944 b thereof.The lower shock plate 892 b is configured to have a majority of thebottom surface 948 b thereof be positioned on/within and secured to themiddle concave portion 912 b of the equalizer arm 886 b, and to have aminority of the bottom surface 948 b thereof be positioned on/andsecured to the outer surface 922 b of the outer pivot tube 888 b. Thecurving of the majority of the bottom surface 948 b of the lower shockplate 892 b is generally commensurate with that at which the middleconcave portion 912 a is curved. The first end 938 b of the lower shockplate 892 b extends a predetermined distance beyond the first planarsurface 894 b of the equalizer arm 886 b and the second end 940 b of thelower shock plate 892 b likewise extends the same predetermined distancebeyond the second planar surface 896 b of the equalizer arm 886 b. Thefirst end 938 b of the convex portion of the lower shock plate 892 b atthe connection of the lower shock plate 892 b to the inner pivot tube890 b, however, does not extend beyond the first end 934 b of the innerpivot tube 890 b.

FIGS. 89-91 illustrate the shock absorber 830, which is preferablyformed of an elastomeric material, such as rubber, and preferablyTORSILASTIC® rubber. The shock absorber 830 has a first planar surface986, a second planar surface 988, and an edge 990 which defines aperimeter of the shock absorber 830. The shock absorber 830 generallyhas first and second portions 992, 993.

The first portion 992 of the shock absorber 830 is generally trapezoidalin configuration such that the edge 990 extends angular downwardly andoutwardly from a flat top 1000 of the shock absorber 830. The edge 990at the connection to the flat top 1000 is generally rounded.

The second portion 993 of the shock absorber 830 is positioned below thefirst portion 992 of the shock absorber 830, and extends to a bottom1002 of the shock absorber 830. From the first portion 992, the edge 990has a first portion 995 which is generally curved/arced in a concavemanner at a first radius downwardly and outwardly and then downwardlyand inwardly. A second portion 997 of the edge 990 is then generallycurved/arced in a concave manner at a second radius downwardly andinwardly and then upwardly and inwardly. A third portion 999 of the edge990 is then generally curved/arced in a convex manner at a third radiusupwardly and inwardly to the bottom 1002. The first radius is largerthan the third radius and the second radius is larger than the firstradius.

The shock absorber 830 is thus generally formed in the shape of anupside-down heart.

A center reference line Y is provided in FIG. 90. The second portion 993of the shock absorber 830 has two apertures 1006, 1008 extendingtherethrough which are planar to one another. Aperture 1006 is providedat a predetermine distance to the left from the center reference line Y,and is preferably provided proximate to the first portion 995 of theedge 990. Aperture 1008 is provided at a predetermined distance to theright from the center reference line Y, and is preferably providedproximate to the first portion 995 of the edge 990. Each of theapertures 1006, 1008 are preferably circular/cylindrical. Apertures1006, 1008 preferably have identical diameters.

FIGS. 77-82, 92, 96 and 97 illustrate the construction of the equalizer800 alone and in conjunction with the suspension system 802, as well asthe function of the equalizer 800 with the suspension system 802. Itshould be noted that the order of the construction of the equalizer 800as described is not the only order in which the equalizer 800 may beconstructed.

The fourth and fifth bushings 834 d, 834 e are inserted and securedwithin the apertures 928 a, 928 b of the inner pivot tubes 890 a, 890 bof the first and second equalizer arm castings 824 a, 824 b,respectively, in the same manner in which the fourth and fifth bushings534 d, 534 e are inserted and secured within the apertures 628 a, 628 bof the inner pivot tubes 590 a, 590 b of the first and second equalizerarm castings 524 a, 524 b, respectively.

The second and third bushings 834 b, 834 c are inserted and securedwithin the apertures 918 a, 918 b of the outer pivot tubes 888 a, 888 bof the first and second equalizer arm castings 824 a, 824 b,respectively, in the same manner in which the second and third bushings534 b, 534 c are inserted and secured within the apertures 618 a, 618 bof the outer pivot tubes 588 a, 588 b of the first and second equalizerarm castings 524 a, 524 b, respectively.

The first bushing 834 a is inserted and secured within the aperture 1010of the upper pivot tube 832 in the same manner in which the firstbushing 534 a is inserted into and secured within the aperture 710 ofthe upper pivot tube 532.

The first and second plug members 836 a, 836 b are inserted into theapertures 1006, 1008 of the shock absorber 830 in the same manner inwhich the first and second plug members 536 a, 536 b are inserted intothe apertures 706, 708 of the shock absorber 530.

The upper pivot tube 832 is positioned within the aperture 858 b of thesecond base plate 820 b such that the second end 1018 of the upper pivottube 832 is substantially flush with the second planar surface 842 b ofthe second base plate 820 b. The outer surface 1014 of the upper pivottube 832 is fixedly secured to the second base plate 820 b, preferablyby welding.

The second side end 952 of the upper shock plate 826 is positioned andsecured against, preferably by welding, the first planar surface 840 bof the second base plate 820 b. The first and second outer ends 954, 956preferably extend slightly beyond the edge 844 b of the second baseplate 820 b at the second portion 548 b thereof. The middle straightportion 966 of the upper shock plate 826 is preferably, thus, positionedbelow the aperture 858 b extending through the second base plate 820 b.The top surface 960 of the middle straight portion 966 of the uppershock plate 826 preferably faces and/or abuts against the outer surface1014 of the upper pivot tube 832.

The second equalizer arm casting 824 b is aligned with the second baseplate 820 b such that the second planar surface 896 b of the equalizerarm 886 b faces the first planar surface 840 b of the second base plate820 b and such that the aperture 1020 e of the fifth bushing 834 e, andthus the aperture 928 b of the inner pivot tube 890 b, are incommunication with the aperture 863 b of the second base plate 820 b.

The first equalizer arm casting 584 a is aligned in an opposite mannersuch that the inner sides 906 a, 906 b of the equalizer arm castings 584a, 584 b face and/or abut against one another, such that the first ends934 a, 934 b of the inner pivot tubes 890 a, 890 b face and/or abutagainst one another, and such that the apertures 1020 d, 1020 e of thefourth and fifth bushings 834 d, 834 e are in communication with oneanother.

The second planar surface 988 of the shock absorber 830 is positioned toface the first planar surface 840 b of the second base plate 820 b. Theflat bottom 1002 of the shock absorber 830 is positioned above the outersurfaces 932 a, 932 b of the inner pivot tubes 890 a, 890 b of the firstand second equalizer arm castings 824 a, 824 b.

At least the second portion 997 of the edge 990 of the shock absorber830 is positioned to rest on the top surfaces 946 a, 946 b of the lowershock plates 892 a, 892 b of the first and second equalizer arm castings824 a, 824 b, with the curve of the second portion 997 of the edge 990of the shock absorber 830 generally matching the curve of the topsurfaces 946 a, 946 b of the lower shock plates 892 a, 892 b.

The bottom surface 960 of the upper shock plate 826 is configured toface and/or abut against the edge 990 of the first portion 992 of theshock absorber 830, with the middle straight portion 966 of the uppershock plate 826 facing and/or abutting against the flat top 1000 of theshock absorber 830.

In this position, the shock absorber 830 is generally encapsulated andsecured between the upper shock plate 826 and the first and secondequalizer arm castings 824 a, 824 b.

The first base plate 820 a is positioned such that the second planarsurface 842 a thereof faces the second planar surface 896 a of the firstequalizer arm 886 a and the first planar surface 894 b of the secondequalizer arm 886 b, and such that the second planar surface 842 athereof faces and/or abuts against the first side end 950 of the uppershock plate 826, the first planar surface 986 of the shock absorber 830,the second end 940 a of the lower shock plate 892 a, the first end 940 bof the lower shock plate 892 b, the second end 936 a of the inner pivottube 890 a, and the first end 934 b of the inner pivot tube 890 b.

The first end 1016 of the upper pivot tube 832 does not extend into theaperture 858 a of the first base plate 820 a, but the aperture 1020 a ofthe first bushing 834 a is in communication with the aperture 858 a ofthe first base plate 820 a. The apertures 1020 d, 1020 e of the bushings834 d, 834 e provided in the apertures 928 a, 928 b of the inner pivottubes 890 a, 890 b are in communication with the aperture 863 a of thefirst base plate 820 a.

The first planar surface 868 b of the second secondary base plate 822 bfaces and/or abuts against the second planar surface 842 b of the secondbase plate 820 b such that the aperture 883 b is in alignment with theaperture 863 b.

The second planar surface 866 a of the first secondary base plate 822 afaces and/or abuts against the first planar surface 840 a of the firstbase plate 820 a such that the aperture 883 a is in alignment with theaperture 863 a.

A fastening member 1050 is inserted through the aperture 883 a of thefirst secondary base plate 822 a, through the aperture 863 a of thefirst base plate 820 a, through the aperture 1020 d of the fourthbushing 834 d, through the aperture 1020 e of the fifth bushing 834 e,through the aperture 863 b of the second base plate 820 b, and throughthe aperture 883 b of the second secondary base plate 822 b such thatthe enlarged head portion 1052 is positioned against the first planarsurface 866 a of the first secondary base plate 822 a A securing member1056 is positioned with the elongated shank portion 1054 extendingthrough the aperture 1058 and the securing member 1056 is positionedagainst the second planar surface 868 b of the second secondary baseplate 822 b.

The equalizer 800 of the invention is thus constructed as illustrated inFIGS. 77-82, 92, 96 and 97. Different fastening members 1050 can beutilized as desired to provide for greasable or non-greasable pivots.

As illustrated in FIG. 77, the equalizer 800 is secured to the centerframe hangar 816 which depends from a frame 1060 of a trailer (notshown). The center frame hangar 816 is generally U-shaped such that ithas a base portion and first and second portions 1064, 1066 which extenddownwardly from opposite ends of the base portion. The base portion isfixedly secured to the frame 1060 of the trailer by known means, such aswelding. The first extending portion 1064 has an aperture (not shown)extending therethrough proximate to a free end thereof. The secondextending portion 1066 has an aperture (not shown) extendingtherethrough proximate to a free end thereof. The aperture of theextending portions 1064, 1066 are in alignment with one another and thefree ends are preferably planar.

As illustrated in FIG. 77, the first and second base plates 820 a, 820 bare positioned between the first and second extending portions 1064,1066 of the center frame hangar 816 such that the first planar surface840 a of the first base plate 820 a faces the first extending portion1064, and such that the second planar surface 842 b of the second baseplate 820 b faces the second extending portion 1066. The aperture 858 aof the first base plate 820 a is in alignment with the aperture of thefirst extending portion 1064 of the center frame hangar 816. Likewise,the aperture 858 b of the second base plate 820 b is in alignment withthe aperture of the second extending portion 1066 of the center framehangar 816. A fastening member, which may be identical to or differentfrom the fastening member 1050 can be inserted through the apertures1068, 858 a, 1020 a, 858 b, 1072. A securing member, which may beidentical to or different from the securing member 1056 can then besecured to the fastening member such that the equalizer 800 is rotatablysecured or pivotally mounted between the first and second extendingportions 1064, 1066 of the center frame hangar 816.

As illustrated in FIG. 77, the suspension system 802 includes theequalizer 800, a front leaf spring 810, a rear leaf spring 814, a frontshackle or link 1080, and a rear shackle or link 1082. As discussed, theequalizer 800 is rotatably secured or pivotally mounted to the centerframe hangar 816 of the frame 1060 of the trailer, illustrated at apoint J. A first end of the front shackle 1080 is rotatably secured orpivotally mounted to the outer pivot tube 888 a of the first equalizerarm casting 824 a, at a point K, preferably by a fastening member and asecuring member. The fastening member extends through apertures of thefront shackle 1080 and the aperture 1020 b of the second bushing 834 b.A first end of the rear shackle 1082 is rotatably secured or pivotallymounted to the outer pivot tube 888 b of the second equalizer armcasting 824 b, at a point L, preferably by a fastening member and asecuring member. The fastening member extends through the apertures ofthe rear shackle 1082 and the aperture 1020 c of the third bushing 834c. The fastening members may be identical to or different from thefastening members 1050. The securing members may be identical ordifferent from the securing members 1056.

A second end of the front shackle 1080 is rotatably secured or pivotallymounted to the rear end 808 of the front leaf spring 810 at a point M. Afront end 1090 of the front leaf spring 810 is attached to a front framehangar 1092 at a point N, or can be directly attached to the frame 1060itself, depending on the configuration of the frame 1060.

A second end of the rear shackle 1082 is rotatably secured or pivotallymounted to the front end 812 of the rear leaf spring 814 at a point P. Arear end of the rear leaf spring 814 is attached to a rear frame hangar1098 at a point Q, or can be directly attached to the frame 1060 itself,depending on the configuration of the frame 1060.

The front axle 804 of the trailer is positioned on the forward leafspring 810 generally equidistantly between point M and point N. The rearaxle 806 is positioned on the rear leaf spring 814 generallyequidistantly between point P and point Q.

It is to be understood that while only a single suspension system 802 isillustrated and described, it is typical to have one suspension system802 provided on both a left and a right side of a trailer. If more thantwo axles are provided on the trailer, it is to be understood that twoor more suspension systems 802 can be provided on both a left and aright side of the trailer.

Like the prior art suspension system 20 including the equalizer 20illustrated in FIG. 1, to the extent possible, road shock and vibrationsfrom tires (not shown) of the trailer, utilizing the suspension system802 including the equalizer 800 of the present invention, aretransferred to the front and rear axles 804, 806, and are absorbed bythe front and rear leaf springs 810, 814, respectively. Points J, N andQ are the contact points through which the road shock is passed to theframe 1060. The equalizer 800 is included in the suspension system 802in order to equalize the weight on both the front and rear axles 804,806 as the tires pass over uneven terrain. For example, an upward motionof the front leaf spring 804 results in a downward motion of the rearleaf spring 806.

The equalizer 800, like the equalizers 100, 500, and unlike theequalizer 22 of the prior art, is configured to dampen or absorb theharsh shocks or vibrations coming off the rear end 808 of the front leafspring 810 and the front end 812 of the rear leaf spring 814 proximateto the center frame hangar 816, thereby allowing for a “softer” ride.

When the front leaf spring 810 moves upward, the equalizer 800 rotatesupwardly and to the left relative to the center hangar 816 about point Jsuch that the rear leaf spring 814 moves downward, thus equalizing theweight on both the front and rear axles 804, 806. Further, when thefront leaf spring 810 moves upward, the first equalizer arm casting 824a rotates or pivots upwardly between the first and second base plates820 a, 820 b by the fastening and securing members 1050, 1056 about apoint V. As the first equalizer arm casting 824 a rotates or pivotsupwardly, the lower shock plate 892 a of the first equalizer arm casting824 a is forced against the second portion 997 of the edge 990 of theshock absorber 830, thus forcing the first portion 992 of the shockabsorber 830 against the upper shock plate 826. Under this force, theshock absorber 830 deforms between the upper and lower shock plates 826,892 a. Upon deformation, the shock absorber 830 absorbs or dampens theharsh shocks or vibrations coming off the rear end 808 of the front leafspring 810, which would otherwise be transferred through the equalizerto the center frame hangar 816 and, thus, to the frame 1060 of thetrailer. Therefore, a “softer” ride is achieved by the suspension system802 including the equalizer 800 of the present invention.

When the rear leaf spring 814 moves upward, the equalizer 800 rotatesupwardly and to the right relative to the center hangar 816 about pointJ such that the front leaf spring 810 moves downward, thus equalizingthe weight on both the front and rear axles 804, 806. Further, when therear leaf spring 814 moves upward, the second equalizer arm casting 824b rotates or pivots upwardly between the first and second base plates820 a, 820 b by the fastening and securing members 1050, 1056 about thepoint V. As the second equalizer arm casting 824 b rotates or pivotsupwardly, the lower shock plate 892 b of the second equalizer armcasting 824 b is forced against the second portion 997 of the edge 990of the shock absorber 830, thus forcing the first portion 992 of theshock absorber 830 against the upper shock plate 826. Under this force,the shock absorber 830 deforms between the upper and lower shock plates826, 892 b. Upon deformation, the shock absorber 830 absorbs or dampensthe harsh shocks or vibrations coming off the front end 812 of the rearleaf spring 814, which would otherwise be transferred through theequalizer to the center frame hangar 816 and, thus, to the frame 1060 ofthe trailer. Therefore, a “softer” ride is achieved by the suspensionsystem 802 including the equalizer 800 of the present invention.

The equalizer 800 of the invention is preferably used for tandem axleconfigurations having a load range of approximately 6,000 to 8,000pounds. For tandem axle configurations having a load range ofapproximately 4,000 to 6,000 pounds, the equalizer 800 of the inventionmay be altered by removing the plug members 836 a, 836 b from within theapertures 1006, 1008 of the shock absorber 830. As stated hereinabove,it has been found that sizing the shock absorber 830 for the load goeshand in hand with performance. It too little or too much material isused in the shock absorber 830, the ride quality will suffer; the twoare linked. Thus, other variations of the shock absorber 830 with,partially with, or without the plug members 836 a, 836 b, can be used asdesired for optimum performance.

When a tri-axle configuration is utilized, generally having a load rangeof approximately up to 21,000 pounds, it is preferable to use theequalizer 500 of the second embodiment, along with an equalizer 1100 ofthe fourth embodiment. The equalizers 500, 1100 are provided for use ina suspension system 1102, as illustrated in FIG. 98, to equalize theweight on the front, middle and rear axles 1104, 1105, 1006 as the tirespass over uneven terrain, as well as to dampen or absorb the harshshocks or vibrations coming off the rear end 1108 of the front leafspring 1110, the front and rear ends 1489, 1487 of the middle leafspring 1105, and the front end 1112 of the rear leaf spring 1114proximate to the two center frame hangars 1116 a, 1116 b, thus allowingfor a “softer” ride. As best illustrated in FIGS. 98-102, the equalizer1100 includes first and second base plates 1120 a, 1120 b, first andsecond secondary base plates 1122 a, 1122 b, an equalizer arm casting1124, an attachment bracket 1125, an upper shock plate 1126, areinforcement plate 1128, a shock absorber 1130, an upper pivot tube1132, and first, second and third bushings 1134 a, 1134 b, 1134 c. Itshould be noted that the configuration of each of these members as shownand described is a preferred configuration of same such that the memberscould be configured in any other suitable manner.

The first and second base plates 1120 a, 1120 b are generally identicalto the first and second base plates 520 a, 520 b of the secondembodiment of the equalizer 500 and, therefore, the first and secondbase plates 1120 a, 1120 b will not be specifically described and/orillustrated with the understanding that like elements in the first andsecond base plates 520 a, 520 b; 1120 a, 1120 b are denoted with likereference numerals.

The first and second secondary base plates 1122 a, 1122 b are generallyidentical to the first and second secondary base plates 522 a, 522 b ofthe second embodiment of the equalizer 500 and, therefore, the first andsecond secondary base plates 1122 a, 1122 b will not be specificallydescribed and/or illustrated with the understanding that like elementsin the first and second secondary base plates 522 a, 522 b; 1122 a, 1122b are denoted with like reference numerals.

The equalizer arm casting 1124 is generally identical to the first andsecond equalizer arm castings 524 a, 524 b of the second embodiment ofthe equalizer 500 and, therefore, the equalizer arm casting 1124 willnot be specifically described and/or illustrated with the understandingthat like elements in the equalizer arm castings 524 a, 524 b; 1124 aredenoted with like reference numerals.

The upper pivot tube 1132 is generally identical to the upper pivot tube532 of the second embodiment of the equalizer 500 and, therefore, theupper pivot tube 1132 will not be specifically described and/orillustrated with the understanding that like elements in the upper pivottube 532, 1132 are denoted with like reference numerals.

The first, second and third bushings 1134 a, 1134 b, 1134 c aregenerally identical to the first, second, third, fourth and fifthbushings 534 a, 534 b, 534 c, 534 d, 534 e of the second embodiment ofthe equalizer 500 and, therefore, the first, second and third bushings1134 a, 1134 b, 1134 c will not be specifically described and/orillustrated with the understanding that like elements in the bushings534 a, 534 b, 534 c, 534 d, 534 e; 1134 a, 1134 b, 1134 c are denotedwith like reference numerals. In this fourth embodiment of the equalizer1100, it should be noted that the first and second bushings 1134 a, 1134b have a longer length than does the third bushing 1134 c.

The upper shock plate 1126 is illustrated in FIGS. 106-108 and isgenerally configured as a half of the upper shock plate 526 of thesecond embodiment of the equalizer 500 with the cut of the upper shockplate 526 occurring through the middle straight portion 666 from thefirst side end 650 to the second side end 652. The upper shock plate1126 is a thin plate which has first and second side ends 1250, 1252,first and second outer ends 1254, 1256, and top and bottom surfaces1258, 1260. The upper shock plate 1126 has, from the first outer end1254 to the second outer end 1256, in series, a first straight portion1262, a curved portion 1264, and a second straight portion 1266. Thecurved portion 1264 is curved downwardly and outwardly from the end ofthe second straight portion 1266, which is not the second side end 652.The first straight portion 1262 extends downwardly and outwardly fromthe curved portion 1264, such that it is at an angle relative to thesecond straight portion 1266.

The reinforcement plate 1128 is illustrated in FIGS. 109 and 110 and isgenerally configured as a half of the reinforcement plate 528 of thesecond embodiment of the equalizer 500, but with an extra cut-outprovided along the edge 1276 thereof, with the cut of the reinforcementplate 528 occurring from a middle of the flat bottom 678 of the edge 676to a middle of the concave portion 686 of the top 684 of the edge 676.The reinforcement plate 1128 is preferably formed of a forged, cast orfabricated metal. The reinforcement plate 1128 has a first planarsurface 1272, a second planar surface 1274, and an edge 1276 whichdefines a perimeter of the reinforcement plate 1128. The edge 1276 ofthe reinforcement plate 1128 has a flat bottom 1278, first and secondsides 1280, 1282, and a top 1284. The first side 1280 is angled upwardlyand inwardly from a first end of the flat bottom 1278 to the top 1284.The second side 1282 extends straight upwardly from a second end of theflat bottom 1278 to the top 1284. The edge 1276 at the connection of thefirst and second sides 1280, 1282 to the flat bottom 1278 is generallyrounded. The edge 1276 at the connection of the first and second sides1280, 1282 to the top 1284 is also generally rounded. The top 1284 has aconcave portion 1286 formed therein which extends from proximate theconnection of the first side 1280 to the top 1284 to the connection ofthe second side 1282 to the top 1284. The second side 1282 has a concaveportion 1287 formed therein which extends from proximate the connectionof the second side 1282 to the flat bottom 1278 to the connection of thesecond side 1282 to the top 1284.

The shock absorber 1130 is illustrated in FIGS. 111-113 and is generallyconfigured as a half of the shock absorber 530 of the second embodimentof the equalizer with the cut of the shock absorber 530 occurring aboutthe center reference line Y, such that the aperture 704 is bisected andsuch that what was the left side of the aperture 704 now defines aconcave portion 1291 of the edge 1290 of the shock absorber 1130. Theshock absorber 1130 is thus generally formed in the shape of half of anupside-down heart.

FIGS. 103-105 illustrate the attachment bracket 1125, which ispreferably formed of a forged, cast or fabricated metal. The attachmentbracket 1125 has an extension member 1450 and a clevis member 1452 whichextends from the extension member 1450.

The extension member 1450 has an interior member 1454 which has firstand second planar surfaces 1456, 1458 connected by a edge (not shown).The first extension member 1450 further has an exterior member 1460which generally surrounds the edge of the interior member 1454. Theexterior member 1460 has first and second ends 1462, 1464 and interiorand exterior edges 1466, 1468. The interior edge 1466 of the exteriormember 1460 is positioned against the edge of the interior member 1454.The first end 1462 of the exterior member 1460 extends beyond the firstplanar surface 1456 of the interior member 1454, and the second end 1464of the exterior member 1460 extends beyond the second planar surface1458 of the interior member 1454.

When viewed in FIG. 104, the extension member 1450 has an aperture 1470formed through the exterior member 1460 proximate to a lower left end ofthereof. The aperture 1470 has a diameter which is preferably identicalto the diameters of the apertures 1162 a, 1164 a of the first and secondbase plates 1120 a, 1120 b, and to the diameters of the apertures 1182a, 1184 a of the first and second secondary base plates 1122 a, 1122 b.

When viewed in FIG. 104, the extension member 1450 has an aperture 1472formed through the exterior member 1460 at a lower end thereof,generally equidistantly between the left and right ends thereof. Theaperture 1472 has a diameter which is preferably identical to thediameter of the aperture 1470.

When viewed in FIG. 104, the clevis member 1452 extends upwardly fromthe top right end of the extension member 1450. The clevis member 1452has first and second arm portions 1474, 1476 which extend from theextension member 1450. Each arm portion 1474, 1476 has inner and outersurfaces 1478, 1480; 1482, 1484 such that the inner surfaces 1478, 1482are generally opposite and spaced from one another. The first armportion 1474 extends proximate to the first end 1462 of the extensionmember 1450 such that the outer surface 1480 of the first arm portion1474 is generally planar with the first end 1462 of the extension member1450. The second arm portion 1476 extends proximate to the second end1464 of the extension member 1450 such that the outer surface 1484 ofthe second arm portion 1476 is generally planar with the second end 1464of the extension member 1450.

The first arm portion 1474 has an aperture 1486 extending therethroughand the second arm portion 1476 has an aperture 1488 extendingtherethrough, which is planar with the aperture 1486 of the first armportion 1474. The apertures 1486, 1488 preferably have identicaldiameters and are preferably identical to the diameters of the apertures1470, 1472 of the extension member 1450. Each of the apertures 1486,1488 preferably has a counterbore 1490, 1492 which opens to the outersurfaces 1480, 1484 of the arm portions 1474, 1476, where thecounterbores 1490, 1492 define larger diameters of the apertures 1486,1488.

FIGS. 98-102 illustrate the construction of the equalizer 1100 alone andin conjunction with the suspension system 1102, as well as the functionof the equalizer 1100 with the suspension system 1102. It should benoted that the order of the construction of the equalizer 1100 asdescribed is not the only order in which the equalizer 1100 may beconstructed.

The third bushing 1134 c is inserted and secured within the aperture1228 of the inner pivot tube 1190 of the first equalizer arm casting1124 in the same manner that the fourth and fifth bushings 534 d, 534 eare inserted and secured within the apertures 628 a, 628 b of the innerpivot tubes 590 a, 590 b of the first and second equalizer arm castings590 a, 590 b, respectively.

The second bushing 1134 b is inserted and secured within the aperture1218 of the outer pivot tube 1188 of the first equalizer arm casting1124 in the same manner that the second and third bushings 534 b, 534 care inserted and secured within the apertures 618 a, 618 b of the outerpivot tubes 588 a, 588 b of the first and second equalizer arm castings524 a, 524 b, respectively.

The first bushing 1134 a is inserted and secured within the aperture1310 of the upper pivot tube 1132 in the same manner that the firstbushing 534 a is inserted and secured within the aperture 710 of theupper pivot tube 532.

The upper pivot tube 1132 is positioned within the aperture 1158 b of,and fixedly secured to, the second base plate 1120 b in the same mannerthat the upper pivot tube 532 is positioned within the aperture 558 bof, and fixedly secured to, the second base plate 520 b.

The second side end 1252 of the upper shock plate 1126 is positioned andsecured against, preferably by welding, the first planar surface 1140 bof the second base plate 1120 b. The first end 1254 is preferably flushwith the edge 1144 b of the second base plate 1120 b at the secondportion 1148 b thereof. The second end 1256 is thus, preferablypositioned between the apertures 1148 b, 1160 b extending through thesecond base plate 1120 b.

The flat bottom 1278 of the edge 1276 of the reinforcement plate 1128 ispositioned to rest on the top surface 1258 of the second straightportion 1266 of the upper shock plate 1126 such that the first planarsurface 1272 of the reinforcement plate 1128 is preferably flush withthe first side end 1250 of the upper shock plate 1126. The outer surface1314 of the upper pivot tube 1132, proximate to the first end 1316thereof, partially rests within the concave portion 1286 of the top 1284of the edge 1276 of the reinforcement plate 1128, such that the firstend 1316 of the upper pivot tube 1132 is preferably flush with the firstplanar surface 1272 of the reinforcement plate 1128.

The equalizer arm casting 1124 is aligned with the second base plate1120 b such that the second planar surface 1196 of the equalizer arm1186 faces the first planar surface 1140 b of the second base plate 1120b and such that the aperture 1320 of the third bushing 1134 c, and thusthe aperture 1228 of the inner pivot tube 1190, are in communicationwith the aperture 1162 b of the second base plate 1120 b.

The second planar surface 1288 of the shock absorber 1130 is positionedto face the first planar surface 1140 b of the second base plate 1120 b.The flat bottom 1302 of the shock, absorber 1130 is positioned above theouter surface 1232 of the inner pivot tube 1190 of the equalizer armcasting 1124.

The edge 1290 about the third portion 1296 of the shock absorber 1130 ispositioned to rest on the top surface 1246 of the lower shock plate 1192of the equalizer arm casting 1124, with the curve of the edge 1290 aboutthe third portion 1296 of the shock absorber 1130 generally matching thecurve of the top surface 1246 of the lower shock plate 1192.

The bottom surface 1260 of the upper shock plate 1126 is configured toface and/or abut against the edge 1290 of the first portion 1292 of theshock absorber 1130, with the second straight portion 1266 of the uppershock plate 1126 facing and/or abutting against the flat top 1300 of theshock absorber 1130.

In this position, the cut-out of the aperture through the shock absorber1130 which resulted in the concave portion 1291 on the edge 1290 of theshock absorber 1130 is in communication with the aperture 1160 b throughthe second base plate 1120 b.

The alignment bracket 1125 is aligned with the second base plate 1120 bsuch that the first planar surface 1456 of the interior member 1454 ofthe alignment bracket 1125 faces the first planar surface 1140 b of thesecond base plate 1120 b, such that the first end 1462 of the exteriormember 1460 of the alignment bracket 1126 faces and possibly partiallyabuts against the first planar surface 1140 b of the second base plate1120 b. As such, the aperture 1472 of the alignment bracket 1125 is incommunication with the aperture 1160 b of the second base plate 1120 b,and the aperture 1470 of the alignment bracket 1125 is in communicationwith the aperture 1164 b of the second base plate 1120 b. The edge 1290,including the concave portion 1291 thereof, of the shock absorber 1130abuts against a portion of the outer edge 1468 of the exterior member1460 of the alignment bracket 1125 and the outer edge 1468 of theexterior member 1460 bends and/or curves around the outer surface of theupper pivot tube 1132.

The first base plate 1120 a is positioned such that the second planarsurface 1142 a thereof faces the first planar surface 1194 of theequalizer arm 1186 and the second planar surface 1458 of the interiormember 1454 of the alignment bracket 1125, and such that the secondplanar surface 1142 a thereof faces and/or abuts against the firstplanar surface 1272 of the reinforcement plate 1128, the first side end1250 of the upper shock plate 1126, the first planar surface 1286 of theshock absorber 1130, the first end 1238 of the lower shock plate 1192,the first end 1234 of the inner pivot tube 1190, and portions of thesecond end 1464 of the exterior member 1460 of the alignment bracket1125.

The first end 1316 of the upper pivot tube 1132 does not extend into theaperture 1158 a of the first base plate 1120 a, but the aperture 1320 aof the first bushing 1134 a is in communication with the aperture 1158 aof the first base plate 1120 a. The aperture 1320 c of the bushing 1134c provided in the aperture 1228 of the inner pivot tube 1190 is incommunication with the aperture 1162 a of the first base plate 1120 a.

The first planar surface 1168 b of the second secondary base plate 1122b faces and/or abuts against the second planar surface 1142 b of thesecond base plate 1120 b such that the aperture 1180 b is in alignmentwith the aperture 1260 b, such that the aperture 1182 b is in alignmentwith the aperture 1162 b, and such that the aperture 1184 b is inalignment with the aperture 1164 b.

The second planar surface 1166 a of the first secondary base plate 1122a faces and/or abuts against the first planar surface 1140 a of thefirst base plate 1120 a such that the aperture 1180 a is in alignmentwith the aperture 1160 a, such that the aperture 1182 a is in alignmentwith the aperture 1162 a, and such that the aperture 1184 a is inalignment with the aperture 1164 a.

A first fastening member 1350 a is inserted through the aperture 1180 aof the first secondary base plate 1122 a, through the aperture 1160 a ofthe first base plate 1120 a, through the aperture 1472 of the alignmentbracket 1125, around the concave portion 1291 of the edge 1290 of theshock absorber 1130, through the aperture 1160 b of the second baseplate 1120 b, and through the aperture 1180 b of the second secondarybase plate 1122 b such that the enlarged head portion 1352 a ispositioned against the first planar surface 1166 a of the firstsecondary base plate 1122 a. A first securing member 1356 a ispositioned with the elongated shank portion 1354 a of the firstfastening member 1350 a extending through the aperture 1358 a of thefirst securing member 1356 a, and the first securing member 1356 a ispositioned against the second planar surface 1168 b of the secondsecondary base plate 1122 b.

A second fastening member 1350 b is inserted through the aperture 1182 aof the first secondary base plate 1122 a, through the aperture 1162 a ofthe first base plate 1120 a, through the aperture 1320 c of the thirdbushing 1134 c, through the aperture 1162 b of the second base plate1120 b, and through the aperture 1182 b of the second secondary baseplate 1122 b such that the enlarged head portion 1352 b is positionedagainst the first planar surface 1166 a of the first secondary baseplate 1122 a. A second fastening member 1356 b is positioned with theelongated shank portion 1354 b of the second fastening member 1350 bextending through the aperture 1358 b of the second securing member 1356b, and the second securing member 1356 b is positioned against thesecond planar surface 1168 b of the second secondary base plate 1122 b.

A third fastening member 1350 c is inserted through the aperture 1184 aof the first secondary base plate 1122 a, through the aperture 1164 a ofthe first base plate 1120 a, through the aperture 1470 of the alignmentbracket 1125, through the aperture 1164 b of the second base plate 1120b, and through the aperture 1184 b of the second secondary base plate1122 b such that the enlarged head portion 1352 c is positioned againstthe first planar surface 1166 a of the first secondary base plate 1122a. A third fastening member 1356 c is positioned with the elongatedshank portion 1354 c of the third fastening member 1350 c extendingthrough the aperture 1358 c of the third securing member 1356 c, and thethird securing member 1356 c is positioned against the second planarsurface 1168 b of the second secondary base plate 1122 b.

The equalizer 1100 is thus constructed as illustrated in FIGS. 98-101.Different fastening members 1350 a, 1350 b, 1350 c can be utilized asdesired to provide for greasable or non-greasable pivots.

As illustrated in FIG. 99, the equalizer 1100 is secured to a firstcenter frame hangar 1116′ which depends from a frame 1360 of a trailer(not shown), and the equalizer 500 is secured to a second center framehangar 1116 a. The center frame hangars 1116, 1116′ are identical to thecenter frame hangar 516 described hereinabove in connection the secondembodiment of the invention and, therefore, will not be described hereinagain for brevity purposes. The equalizers 500, 1100 are also rotatablysecured or pivotally mounted to the center frame hangars 1116, 1116′ inthe same manner in which the equalizer 500 is rotatably secured orpivotally mounted to the center frame hangar 516.

The suspension system 1102 includes the equalizers 500, 1100, a frontleaf spring 1110, a middle leaf spring 1111, a rear leaf spring 1114, afirst front shackle or link 1380, a second front shackle or link 1380′,and a rear shackle or link 1382. As discussed, the equalizer 500 isrotatably secured or pivotally mounted to the second frame hangar 1116of the frame 1360 of the trailer, illustrated at point J. A first end ofthe first front shackle 1380 is rotatably secured or pivotally mountedto the equalizer 500, as described hereinabove, at a point K. A firstend of the rear shackle 1382 is rotatably secured or pivotally mountedto the equalizer 500, as described hereinabove, at a point L.

A second end of the first front shackle 1380 is rotatably secured orpivotally mounted to a rear end 1487 of the middle leaf spring 1111 at apoint M. A front end 1489 of the middle leaf spring 1111 is fixedlyattached to the clevis member 1452 of the attachment member 1125 of theequalizer 1100 at a point P′.

A second end of the rear shackle 1382 is rotatably secured or pivotallymounted to the front end 1112 of the rear leaf spring 1114 at a point P.A rear end of the rear leaf spring 1114 is attached to a rear framehangar 1398 at a point Q, or can be directly attached to the frame 1360itself, depending on the configuration of the frame 1360.

A first end of the second front shackle 1380′ is rotatably secured orpivotally mounted to the outer pivot tube 1188 of the equalizer armcasting 1124, at a point K, by a fastening member and a securing member.

A second end of the second front shackle 1380′ is rotatably secured orpivotally mounted to the rear end 1108 of the front leaf spring 1110 ata point M′. A front end of the front leaf spring 1110 is attached to afront frame hangar 1392 at a point N, or can be directly attached to theframe 1360 itself, depending on the configuration of the frame 1360.

The front axle 1104 of the trailer is positioned on the forward leafspring 1110 generally equidistantly between point N and point M′. Themiddle axle 1105 of the trailer is positioned on the middle leaf spring1111 generally equidistantly between point P′ and point M. The rear axle1106 of the trailer is positioned on the rear leaf spring 1114 generallyequidistantly between point P and point Q.

It is to be understood that while only a single suspension system 1102is illustrated and described, it is typical to have one suspensionsystem 1102 provided on both a left and a right side of a trailer.

When utilizing the suspension system 1102 including the equalizers 500,1100 of the present invention, to the extent possible, road shock andvibrations from tires (not shown) of the trailer are transferred to thefront, middle and rear axles 1104, 1105, 1106, and are absorbed by thefront, middle and rear leaf springs 1110, 1111, 1114 respectively.Points N, J′, J, Q are the contact points through which the road shockis passed to the frame 1360. The equalizers 500, 1100 are included inthe suspension system 1102 in order to equalize the weight between thefront, middle and rear axles 1104, 1105, 1106 as the tires pass overuneven terrain. For example, an upward motion of the front leaf spring1110 results in a downward motion of the middle leaf spring 1111, whichresults in an upward motion of the rear leaf spring 1114.

The equalizers 500, 1100 are configured to dampen or absorb the harshshocks or vibrations coming off the leaf springs 1110, 1111, 1114proximate to the center hangars 1116, 1116′, thereby allowing for a“softer” ride.

Operation of the suspension system 1102 with the equalizers 500, 1100therein is similar to the operation of the suspension system 502 withthe equalizer 500 therein. The equalizer 1100 is configured differentlyfrom the equalizer 500, however, in order to provide stabilization tothe suspension system 1102, which is necessary because of the tri-axleconfiguration of the suspension system 1102. The alignment bracket 1125is not rotatably secured or pivotally mounted, but rather is fixed intoposition, such that the alignment bracket 1125 permits only stabilizedupward or downward movement of the middle leaf spring 1111.

It should be noted that if desired, the equalizer 1100 could also beutilized with the equalizer 800 of the third embodiment, or that theequalizer 1100 could be modified to be similar to the equalizer 800 ofthe third embodiment, rather than similar to the equalizer 500 of thesecond embodiment. Plug member and spacers, such that those used in theequalizer 500, could also be included in the shock absorber 1130 of theequalizer 1100 as desired.

FIGS. 114-123 illustrate a fifth embodiment of a equalizer 1500. Thisfifth embodiment has been found to reduce pulsations of the shockabsorber 1530 and increase load capacity and provide a “softer” ride.Equalizer 1500 can be used in conjuncture with suspension systems 102,502, 802, and 1102. The equalizer 1500 includes first and second baseplates 1520 a, 1520 b, first and second secondary base plates 1522 a,1522 b, first and second equalizer arm castings 1514 a, 1514 b, an uppershock plate 1528, a shock absorber 1530, an upper pivot tube 1532, andfirst, second, third, fourth and fifth bushings 1534 a, 1534 b, 1534 c,1534 d, 1534 e.

The upper shock plate 1526 is generally identical to the upper shockplate 526 of the second embodiment of the equalizer 500. The upper shockplate 1526 is welded to both the first and second base plates 1520 a,1520 b. Welding the upper shock plate 1526 on both sides increases theamount of shock it is able to withstand.

The upper pivot tube 1532 is generally identical to the upper pivot tube532 of the second embodiment of the equalizer 500. The bushings 1534 a,1534 b, 1534 c, 1534 d, 1534 e are generally identical to the bushings534 a, 534 b, 534 c, 534 d, 534 e of the second embodiment of theequalizer 500.

FIG. 118 illustrates the first base plate 1520 a, and FIG. 119illustrates the second base plate 1520 b with the upper shock plate 1526attached. The first base plate 1520 a is preferably identical in shapeand configuration to the second base plate 1520 b and, as such, only thefirst base plate 1520 a is described with the understanding that thedescription of the second base plate 1520 b would be identical. Theelements of the first base plate 1520 a will have reference numeralsending in “a”. As such, it is to be understood that the elements of thesecond base plate 1520 b will have like reference numerals ending in“b”.

The first base plate 1520 a is preferably formed of a forged, cast orfabricated metal. The first base plate 1520 a has a first planar surface1540 a, a second planar surface 1542 a on the opposite side (notillustrated), and an edge 1544 a which defines a perimeter of the firstbase plate 1520 a. The first base plate 1520 a generally has first,second, third and fourth portions 1546, 1548 a, 1550 a, 1552 a.

The first portion 1546 a of the first base plate 1520 a is generallytriangular in configuration such that the edge 1544 a extends angularlydownwardly and outwardly from a top 1554 a of the first base plate 1520a. The edge 1544 a at the top 1554 a of the first portion 1546 a isgenerally rounded.

The second portion 1548 a of the first base plate 1520 a extendsdownwardly for a length from the first portion 1546 a and then turnsoutwardly along a rounded path to the start of the third portion 1550 a.The edge 1544 a at the connection of the first and second portions 1546a, 1548 a is generally rounded.

The third portion 1550 a of the first base plate 1520 a is generally “U”shaped in configuration such that the edge 1544 a extends inwardly for alength, downwardly for a length and then outwardly for a length from thesecond portion 1548 a to the fourth portion 1552 a. The edge 1544 a atthe connection of the second and third portions 1548 a, 1550 a isgenerally rounded.

The fourth portion 1552 a of the first base plate 1520 a is generallytriangular in configuration such that the edge 1544 a extends angularlydownwardly and inwardly from the third portion 1550 a to a bottom 1556 aof the first base plate 1520 a. The edge 1544 a at the connection of thethird and fourth portions 1550 a, 1552 a is generally rounded and theedge 1544 a at the bottom 1556 a of the fourth portion 1552 a isgenerally rounded.

A center reference line Y is provided in FIG. 118. An aperture 1558 aextends through the first base plate 1520 a. The aperture 1558 a isgenerally bisected by the first and second portions 1546 a, 1548 a, andby the center reference line Y. The fourth portion 1552 a of the firstbase plate 1520 a has an aperture 1563 a extending therethroughproximate to the bottom 1556 a, which is generally bisected by thecenter reference line Y. The third portion 1550 a of the first baseplate 1520 a has an aperture 1564 a extending therethrough, which isgenerally bisected by the center reference line Y. Each of the apertures1558 a, 1563 a, and 1564 a are preferably circular/cylindrical. Aperture1558 a has a diameter which is larger than a diameter of the aperture1563 a and 1564 a. Aperture 1563 a and 1564 a are roughly the same size.

The first secondary base plates 1522 a are similar in shape andconfiguration to the second secondary base plates 1522 b and, as such,only the first secondary base plate 1522 a is described with theunderstanding that the description of the second secondary base plates1522 b would be identical. The elements of the first secondary baseplate 1522 a will have reference numerals ending in “a”. As such, it isto be understood that the elements of the second secondary base plate1522 b will have like reference numerals ending in “b”.

FIG. 117 illustrates the first secondary base plate 1522 a, which ispreferably formed of a forged, cast or fabricated metal. The firstsecondary base plates 1522 a are formed in a shape of a circular disc orwasher. Multiple first secondary base plates 1522 a are used together tooffer additional support.

The second equalizer arm casting 1524 b is preferably identical in shapeand configuration to the first equalizer arm casting 1524 a and, assuch, only the second equalizer arm casting 1524 b is described with theunderstanding that the description of the first equalizer arm casting1524 a would be identical. The elements of the second equalizer armcasting 1524 b will have reference numerals ending in “b”.

The first equalizer arm casting 1524 a and second equalizer arm casting1524 b are generally the same as the first equalizer arm casting 824 aand second equalizer arm casting 824 b described earlier for the thirdembodiment described above and as illustrated in FIGS. 85-88. As such,the details of first equalizer arm casting 1524 a and second equalizerarm casting 1524 b will not be described further.

FIG. 120 illustrates the shock absorber 1530, which is formed of thesame material and has the same general shape as shock absorber 830 forthe third embodiment described above and as illustrated in FIGS. 89-91.The shock absorber 1530 has a first planar surface 1686, a second planarsurface 1688 (not illustrated) opposite the first planar surface 1686,and an edge 1690 which defines a perimeter of the shock absorber 1530.

The shock absorber 1530 does not, however, have the first and secondplug members 836 a, 836 b which are inserted into the apertures 1006,1008 of the shock absorber 830. Instead, the shock absorber 1530 has acentral aperture 1704 extending therethrough. Aperture 1704 is providedin the center of the shock absorber 1530 aligned to correspond withaperture 1564 a in first base plate 1520 a and aperture 1564 b in secondbase plate 1520 b. Aperture 1707 is preferably circular/cylindrical.Removing the non-centrally located apertures 1006 and 1008 of the thirdembodiment equalizer 800 reduces pulsations in the shock absorber 1530and thereby further increases load capacity and provides a smootherride. It is understood that additional central apertures 1530 can beadded without departing from the scope of this disclosure.

The construction of the equalizer 1500 is generally the same asequalizer 800 and equalizer 1530 functions with the suspension system802 in the same way as equalizer 800. As such, the description of theconstruction of the equalizer 1500 will be limited to the differencesfrom equalizer 800.

As noted before, equalizer 1500 does not have first and second plugmembers 836 a, 836 b or apertures 1006, 1008 like equalizer 800.Equalizer 1500 has a single aperture 1704 into which a sleeve 1538 isinserted. The sleeve 1538 may either be secured within the aperture 1704or simply inserted within the aperture 1704. FIGS. 121-123 illustratethe sleeve 1538, which is preferably formed of a plastic material. Thesleeve 1538 is a cylindrical member having an aperture 1736 extendingentirely therethrough such that inner and outer surfaces 738, 740 of thesleeve 1538 are defined. The sleeve 1538 extends from a first end 1742thereof to a second end 1744 thereof. The inner surface 1738 of thesleeve 1538 at each of the first and second ends 1742, 1744 ispreferably chamfered.

A fastening member 1750 is inserted through the first secondary baseplates 1522 a, the aperture 1563 a of the first base plate 1520 a, thefourth bushing 1534 d, the fifth bushing 1534 e, aperture 1563 b of thesecond base plate 1520 b, and the second secondary base plates 1522 b.Another fastening member 1750 is inserted through the first secondarybase plates 1522 a, the aperture 1564 a of the first base plate 1520 a,the aperture 1736 of the sleeve 1538 inside aperture 1704 of theequalizer 1539, aperture 1564 b of the second base plate 1520 b, and thesecond secondary base plates 1522 b.

The fastening members 1750 include a head portion 1752 sufficientlylarge so as not to fit through first secondary base plates 1522 a.Fastening members 1750 a also include a thread portion 1754 opposite thehead portion 1752. The thread portions 1754 extend beyond the secondsecondary base plates 1522 b. Cap nuts 1756 or the like are threadedonto the thread portions 1754 at end of the fastening members 1750.

The equalizers 100, 500, 800, 1100, 1500 and suspension systems 102,502, 802, 1102 are advantageous and beneficial for a “softer” ride incomparison to the prior art equalizer 22 and the prior art suspensionsystem 20 which includes the prior art equalizer 22.

While preferred embodiments of the invention are shown and described, itis envisioned that those skilled in the art may devise variousmodifications without departing from the spirit and scope of theforegoing description and the appended claims.

1. An equalizer for use in a suspension system of a vehicle having aframe, said equalizer comprising: a first plate which is pivotallymounted to the frame of the vehicle; at least one equalizer armpivotally mounted to said first plate, said at least one equalizer armbeing operatively attached to the suspension system; and a shockabsorber which is positioned at least partially against said at leastone equalizer arm, said shock absorber configured to absorbshock/vibrations transferred to said at least one equalizer arm from thesuspension system, wherein said shock absorber has a centrally locatedaperture extending therethrough.
 2. The equalizer as defined in claim 1,wherein said equalizer has first and second equalizer arms.
 3. Theequalizer as defined in claim 2, wherein said equalizer is generallyheart-shaped.
 4. The equalizer as defined in claim 2, wherein said firstequalizer arm is pivotally mounted to said second equalizer arm.
 5. Theequalizer as defined in claim 1, further comprising an alignment bracketwhich is fixedly mounted to said first plate, said alignment bracketbeing operatively attached to the suspension system, said shock absorberbeing at least partially positioned against said alignment bracket. 6.The equalizer as defined in claim 5, wherein said shock absorber isgenerally shaped like a half of a heart.
 7. The equalizer as defined inclaim 1, wherein said shock absorber is generally shaped like a half ofa heart.
 8. The equalizer as defined in claim 1, wherein said shockabsorber is generally half heart-shaped.
 9. The equalizer as defined inclaim 1, further including a second plate which is fixedly secured tosaid first plate, said shock absorber being at least partiallyencapsulated between said second plate and said at least one equalizerarm.
 10. The equalizer as defined in claim 9, wherein said second plateis configured to conform around at least a portion of said shockabsorber.
 11. The equalizer as defined in claim 1, wherein said at leastone equalizer arm includes a lower shock plate, said lower shock plateis configured to conform around at least a portion of said shockabsorber.
 12. The equalizer as defined in claim 9, further including aupper shock plate located between said first plate and said second plateconfigured to conform to at least a portion of a top of said shockabsorber.
 13. The equalizer as defined in claim 12, wherein said uppershock plate is welded to both said first plate and said second plate.12. The equalizer as defined in claim 1, wherein said shock absorber isat least partially formed of an elastomeric material.
 15. The equalizeras defined in claim 1, further including a spacer which is positionedwithin said central aperture, and further including a fastening memberwhich extends through said spacer in order to fixedly secure said shockabsorber to said first plate.
 16. The equalizer as defined in claim 1,further including a second plate, said second plate being pivotallymounted to the frame of the vehicle, said at least one equalizer armbeing pivotally mounted to said second plate, said shock absorber andsaid at least one equalizer arm being at least partially positionedbetween said first and second plates.
 17. A suspension system for avehicle having a frame and front and rear axles, said suspension systemcomprising: a front spring member having first and second ends, saidfirst end being attached to the frame of the vehicle, said front springmember supporting the front axle; a rear spring member having first andsecond ends, said second end being attached to the frame of the vehicle,said rear spring member supporting the rear axle; an equalizer pivotallymounted to the frame of the vehicle, said equalizer including: a firstplate, said first plate being pivotally mounted to the frame of thevehicle; first and second equalizer arms pivotally mounted to said firstplate, said first equalizer arm being operatively attached to saidsecond end of said front spring member, said second equalizer arm beingoperatively attached to said first end of said rear spring member; and ashock absorber which is at least partially positioned against each ofsaid first and second equalizer arms, said shock absorber configured toabsorb shock/vibrations transferred to said first and second equalizerarms from said front and rear spring members when the front and rearaxles are moved upwardly and downwardly, wherein said shock absorber hasa centrally located aperture extending therethrough.
 18. The suspensionsystem as defined in claim 17, wherein said first equalizer arm isattached to said second end of said front spring member by a firstshackle, and wherein said second equalizer arm is attached to said firstend of said rear spring member by a second shackle.
 19. The suspensionsystem as defined in claim 17, wherein said first equalizer arm ispivotally mounted to said second equalizer arm.
 20. The suspensionsystem as defined in claim 17, wherein said front and rear springmembers are leaf springs.
 21. The suspension system as defined in claim17, wherein said shock absorber is generally heart-shaped.
 22. Thesuspension system as defined in claim 17, wherein said shock absorber isat least partially formed of an elastomeric material.
 23. A suspensionsystem for a vehicle having a frame, first and second outer axles, and amiddle axle, said suspension system comprising: a first outer springmember having first and second ends, said first end being attached tothe frame of the vehicle, said first outer spring member supporting thefirst outer axle; a middle spring member having first and second ends,said middle spring member supporting the middle axle; and a firstequalizer pivotally mounted to the frame of the vehicle, said equalizerincluding: a first plate which is pivotally mounted to the frame of thevehicle, an equalizer arm pivotally mounted to said first plate, saidequalizer arm being operatively attached to said second end of saidfirst outer spring member, an alignment bracket fixedly mounted to saidfirst plate, said alignment bracket being operatively attached to saidfirst end of said middle spring member, and a shock absorber which is atleast partially positioned against said equalizer arm, said shockabsorber configured to absorb shock/vibrations transferred to saidequalizer arm when the first outer spring member is moved upwardly,wherein said shock absorber has a centrally located aperture extendingtherethrough.
 24. The suspension system as defined in claim 23, whereinsaid shock absorber is at least partially formed of a flexible rubbermaterial.
 25. The suspension system as defined in claim 23, wherein saidshock absorber is generally shaped as a half of a heart.
 26. Thesuspension system as defined in claim 23, wherein said shock absorber isat least partially positioned against said alignment bracket.
 27. Thesuspension system as defined in claim 23, further comprising: a secondouter spring member having first and second ends, said second end beingattached to the frame of the vehicle, said second outer spring membersupporting the second outer axle; and a second equalizer pivotallymounted to the frame of the vehicle, said second equalizer including: afirst plate which is pivotally mounted to the frame of the vehicle,first and second equalizer arms pivotally mounted to said first plate ofsaid second equalizer, said first equalizer arm being operativelyattached to said second end of said middle spring member, said secondequalizer arm being operatively attached to said first end of saidsecond outer spring member, and a shock absorber which is at leastpartially positioned against said first and second equalizer arms ofsaid first equalizer, said shock absorber of said second equalizerconfigured to absorb shock/vibrations transferred to said first andsecond equalizer arms when the middle and second outer spring membersare moved upwardly, wherein said shock absorber has a centrally locatedaperture extending therethrough.
 28. The suspension system as defined inclaim 27, wherein said shock absorber of said second equalizer is atleast partially formed of a flexible rubber material.
 29. The suspensionsystem as defined in claim 27, wherein said shock absorber of saidsecond equalizer is generally heart-shaped.